UBC Theses and Dissertations

UBC Theses Logo

UBC Theses and Dissertations

Interrelation between thyroid function and vitamin A in avian metabolism Coates, Viona 1971

Your browser doesn't seem to have a PDF viewer, please download the PDF to view this item.

Item Metadata

Download

Media
831-UBC_1971_A6_7 C63.pdf [ 4.56MB ]
Metadata
JSON: 831-1.0101798.json
JSON-LD: 831-1.0101798-ld.json
RDF/XML (Pretty): 831-1.0101798-rdf.xml
RDF/JSON: 831-1.0101798-rdf.json
Turtle: 831-1.0101798-turtle.txt
N-Triples: 831-1.0101798-rdf-ntriples.txt
Original Record: 831-1.0101798-source.json
Full Text
831-1.0101798-fulltext.txt
Citation
831-1.0101798.ris

Full Text

INTERRELATION BETWEEN THYROID FUNCTION AND VITAMIN A IN AVIAN METABOLISM BY VIONA COATES A THESIS SUBMITTED IN PARTIAL FULFILMENT OF ' THE. REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE in the Department of POULTRY SCIENCE We accept this thesis as conforming to the required standard THE UNIVERSITY OF BRITISH COLUMBIA May, 1971 In presenting this thesis in partial fulfilment of the requirements for an advanced degree at the University of British Columbia, I agree that the Library shall make it freely available for reference and study. I further agree that permission for extensive copying of this thesis for scholarly purposes may be granted by the Head of my Department or by his representatives. It is understood that copying or publication of this thesis for financial gain shall not be allowed without my written permission. Department of The University of British Columbia Vancouver 8, Canada ABSTRACT Three approaches were made to study the i n t e r r e l a t i o n s between thyroid function and vitamin A i n avian metabolism. These were a h i s t o l o g i c a l assessment of the a c t i v i t y of the thyroid gland as i t i s affected by hypervitaminosis A, the e f f e c t of hypervitaminosis A on the incubation time of eggs in j e c t e d with d i f f e r e n t l e v e l s of vitamin A alcohol and palmitate, and f i n a l l y the e f f e c t s of hypervitaminosis A on t h y r o i d a l uptake and release of radioiodine by chickens. These studies yielded the following observations. CI) H i s t o l o g i c a l -jiieasurements indicated that dietary hypervitaminosis A can depress the secretion of thyroid stimulating hormone. (2) The e f f e c t of hypervitaminosis A on thyroid a c t i v i t y as affected by environmental temperature. (3) Vitamin A palmitate and alcohol prolong incubation time. The alcohol form has, i n addition, an adverse e f f e c t on embryonic development which i s manifested i n hemorrhaging and malformation of the embryo. (4) Vitamin A i n excess may either depress or stimulate t h y r o i d a l uptake of radioiodine depending upon an u n i d e n t i f i e d component of the environment. (5) Vitamin A i n excess a f f e c t s the endocrine system. This i s indicated by an increase i n si z e of the thyroid and adrenal glands and a decrease i n s i z e of combs and testes. - I l l _ TABLE OF CONTENTS .ABSTRACT . TABLE OF CONTENTS . . • LIST OF FIGURES . LIST OF TABLES ACKNOWLEDGEMENTS -INTRODUCTION PART I: EFFECT OF HYPERVITAMINOSIS A ON INCUBATION TIME . Experimental Preliminary Experiment .. Experiment 1 Experiment 2 • Experiment 3 ........ Results and Discussion PART II: EFFECT OF HYPERVITAMINOSIS A ON THYROID ACTIVITY HISTOLOGICAL ASSESSMENT . ... . Experimental Experiment 1 Experiment 2 • Experiment 3 • Results and Discussion .... PART III: EFFECT OF HYPERVITAMINOSIS ON THYROIDAL UPTAKE AND RELEASE OF IODINE Experimental - iv -Page Results ' 33 Discussion .......... 45.. Oxygen consumption . . .. Al Breast muscle temperature \ 47 Adrenal weights '48 Testes and combs •.. 48-Summary .• •.. 49 REFERENCES • ' • • • 5 1 Appendix , 59 LIST OF FIGURES Figure Page 1 Thyroid gland of a White Leghorn female chicken on a diet containing a normal level of vitamin A ... 27 2 Thyroid gland of White Leghorn female chicken on a diet containing 200,000 IU vitamin A per kgm basal diet 27 Thyroid gland of a White Leghorn female chicken on a diet containing 400,000 IU vitamin A per kgm basal diet Thyroid gland of a White Leghorn male chicken on a diet containing a normal level of vitamin A Thyroid gland of a White Leghorn male chicken on a diet containing 400,000 IU of vitamin A per kgm basal diet ........ Percent colloid present in thyroid gland of the female and male chicken and the male quail 28 29 29 30 7 Thyroidal uptake and release of radioiodine in chicks fed normal and excessive levels of vitamin A in experiment 1 40 8 Thyroidal uptake and release of radioiodine in chicks fed normal and excessive levels of vitamin A in experiment 1 '41 9 Thyroidal uptake and release of radioiodine in chicks fed normal and excessive levels of vitamin A in experiment 2 42 10 Thyroidal uptake and release of radioiodine i n chicks fed normal and excessive levels of vitamin A in experiment 2 43 11 Testes from male chicken on a normal level of vitamin A 44 12 Testes from male chicken on a diet containing an excess level of vitamin A 44 - v i -LIST OF TABLES Table Page 1 Mortality of embryos in vitamin A injected eggs...... 17 2 Rate of hatchability, % of total hatch at 20-21st day over the total hatch at 22nd day 18 3 Analysis of vitamin A in livers of newly hatched chicks 18 4 Effect of vitamin A palmitate on the activity of the thyroid gland as indicated by % colloid in the thyroid gland, in the female chicken 25 5 Result of Duncan's Multiple range test for % epithelial tissue in thyroid gland 25 6 Effect of vitamin A palmitate on the activity of the thyroid gland as indicated by % colloid in the thyroid gland, of the male chicken 26 7 Effect of vitamin A palmitate and temperature on the activity of the thyroid gland in the Japanese quail 26 131 8 Mean thyroid weights and I uptake values for control and treated birds (S.D.) in experiment 1 36 131 9 Mean thyroid weight and I uptake values for control and treated birds (S.D.) in experiment 2 37 10 Effect of vitamin A on the mean body weight, 02 con-sumption, temperature, testes and comb weight i n experiment 1 38 11 The relationship between testes weight, degree of differentiation and breast muscle temperature 38 12 Effect of an excess of vitamin A on the mean thyroid weight, adrenal and body weights of chicks in experiment 2 39 13 Composition of the basal diet for White Leghorn' male chickens 60 14 Composition of the all-mash quail diet 61 15 Composition of the basal diet of chickens in the thyroidal uptake and release studies 62 16 Analysis of variance of the % colloid in the thyroid gland . ... 63 - v i i -Table Page 131 17 Analysis of variance of I uptake % of total dose in experiment 1 64 131 18 Analysis of variance of I uptake % per mg thyroid weight in experiment 1 65 131 19 Analysis of variance of I uptake % of administered dose in experiment 2 66 131 20 Analysis of variance of I uptake % per mg of thyroid weight in experiment 2 67 21 Analysis of variance of body weight, breast muscle temperature, oxygen consumption, thyroid, testes and comb weight per gm body weight in experiment 1 .. 68 22 Analysis of variance for the thyroid, adrenal and body weight for White Leghorn chicks on a normal level of vitamin A in experiment 2 69 -- v i i i -ACKNOWLEDGEMENTS The author wishes to express her appreciation to Professor B.E. March of the Department of Poultry Science who originally suggested the study and supervised the research reported herein. The academic stimulation and continued interest in both the experimental research and the preparation of the manuscript by Dr. J. Biely of the Department of Poultry Science is deeply appreciated. Grateful acknowledgement i s also extended by the author for the valuable advice in the preparation of the manuscript to Dr. W.D. Kitts, Chairman of the Departments of Animal Science and Poultry Science, to Dr. R.C. Fitzsimmons of the Department of Poultry Science and Dr. P. Ford of the Department of Zoology. The f a c i l i t i e s required for the completion of this study were generously provided by the Department of Poultry Science. - 1 -INTRODUCTION AND REVIEW OF THE LITERATURE The treatment of hens with thyroxine has been found to render the hatched chicks hypothyroid (Wheeler, et a l . 1948). Such treatment was also found to increase the incubation time (P < 0.01) of the hen's eggs. The hypothyroid chick was considered to be due to either a deficiency of maternal thyroid hormone or ineffective function-ing of the embryonic thyroidl .during the latter part of incubation. Bates, R.W. et a l . (1941), demonstrated that in newly-hatched chicks there was a threshold dosage in the response of the thyroid gland to injected thyroxine. They also demonstrated a genetic difference between strains in their a b i l i t y to respond to progressively larger dosages of thyroxine. McCartney and Shaffner (1948) found that feeding of thiouracil to hens at levels of 0.1% and 0.3%,the chicks resulted in an increase in thyroid size by a factor of 1.5-2.75. McCartney and Shaffner (1950) observed a 25% decrease in hatchability after feeding 0.3% thiouracil to New Hampshire hens for four weeks. Riddle (1930) suggested that a maternal thyroid hormone was involved. This hormone was thought to be responsible for regulating the rate of embryonic development and hence the length of the incubation period. Similar findings were made by Riddle," (1930) : and Hollander and Riddle (1946) - 2 -who observed that eggs from pigeons with naturally occurring goiter required a longer incubation period. When the birds were treated with iodine supplementation the goiter was corrected and the hatching time also reduced to normal. Differences in thyroid activity may also result from differences in genetic constitution. The Frizzle fowl provides a good example. Disturbances of the metabolism in Frizzle fowl has been demonstrated by Landauer (1946) to have an effect on hatchability. According to Landauer and Dunn (1930) and Hutt, (1930) because of an incompletely dominant mutation, these breeds of fowl have wavy (heterozygous) or curly (homozygous) feathers. The feathers tend to break off easily, thus leaving the fowl naked. Benedict,. Landauer and Fon (1932) reported that featherlessness results in body heat loss and consequently an increased rate of metabolism. Such disturbances in temperature regulation manifested by an increase in the rate of metabolism are associated changes in the activity of the thyroid gland. Landauer and Dunn (1930) in their studies on hatchability in Frizzle mating, found that the hatching quality of eggs lai d by homozygous Frizzle hens is reduced. This is also the case in eggs from heterozygous Frizzle hens. The differences in hatchability were, 42.7% in the cross of homozygous Frizzle hen by a normal cock, and 75.3% in a mating of a normal hen with a pure Frizzle male. This suggests that the differences are due to maternal physiology. Abrele and Landauer (1935) demonstrated that day-old homozygous Frizzle chicks had larger thyroid glands compared with White Leghorn controls. Landauer et a l . (1949) reported that Frizzle hens cannot always deposit in their eggs - 3 -a l l the essential substances necessary for normal development. The result i s an increased embryonic mortality. In agreement with these findings are the observations of Abbott and Asmundson (1957). These investigators reported that eggs from almost bare chickens are homozygous for the "scaleless" mutation. Similar findings have been made by Smythe (1954) who experimented with eggs lai d by turkeys with the "hairy" feather defect. Ukita (1949) found that the offspring of rabbits which were thyroidectomized during pregnancy required a longer gestation period. Their offspring also had hypertrophied thyroids. The importance of the environment in modifying the activity of the thyroid gland i s well recognized (Rand, et a l . 1952). Low environmental temperatures increase thyroid activity and have also been found to increase hatchability time (Mussechl, et a l . , 1924-25; Warren, 1934; Funk, 1934). In addition to genetic and environment factors dietary factors also exert an influence on the thyroid gland as well as on the hatchability of the hens egg. Temperton,:and Dudley- (1947) suggest that excessive amounts of dietary vitamin A may lead to a condition of hypervitaminosis resulting in an increase in embryonic mortality. The minimum amount of vitamin A in an egg, necessary for hatching, according to Lissot, " and Coridroid, (1941) is 350 international units. Boelum, * , (1948) suggests 400 units vitamin A for Brown Leghorn pullets. Taylor,'" et a l . (1947) recommend a minimum .of 2,000 IU of pro-vitamin A per lb. of feed. According to Rubin, and Bird (1942) more vitamin A is needed for maximum production than for maximal hatchability. - 4 -Thompson, (1969) demonstrated that hens fed retinoic acid; although their rate of egg production and f e r t i l i t y was high, their eggs failed to hatch. The embryonic development was normal up to 48 hours, thereafter the appearance was markedly abnormal. Similar results were obtained from retinoic acid fed Japanese quail. Thompson attributed the embryonic abnormalities to vitamin A deficiency result-ing from the in a b i l i t y of the hen to transfer the retinoic acid and i t s derivatives to the egg. Thompson showed that eggs injected with retinoic acid caused embryos to die at early stages of incubation. Retinoic acid toxicity may be similar to the hypervitaminosis A syndrome observed in rats (Thompson, et a l . (1960)). The form of vitamin ' A determined how readily i t can be utilized and stored by the body. Dietary retinyl esters entering the small intestine are hydrolyzed by a pancreatic or mucosal enzyme. Retinol crosses the c e l l membrane and is promptly re-esterified and carried by a lipoprotein via the lymphatics to the liver (Huang and Goodman, 1965). In many species the ratio of esterified retinol to free retinol is about 20 to 1 in the l i v e r . According to Sadhu, - .(1947) vitamin A depresses the metabolic rate and reduces the thyroid size of normal, thiouracil-treated and thyroxine-treated rats. Evidently vitamin A partially counteracts the high oxygen consumption produced by thyroid feeding. When Rappai, and Rosenfed • (19.35) injected thyroxine, oxygen consumption was increased to 42.4% but when vitamin A and thyroxine were administered simultaneously there - 5 -was a rise of only 13%. The administration of carotene and thyroxine gave a rise of only 10%. Abelin (1935) administered thyroxine to rats and got a rise of 50% in oxygen consumption. When he administered both vitamin A and thyroxine he obtained a rise of only 20%. Similar results were obtained by Lagaras and Drummond (1938) and Belasco . and Murlin (1940). Smith and Perman (1940) administered thyroxine to cats and obtained an increase in oxygen consumption of 45.7% when they administered both carotene and thyroxine they obtained a rise of only 25.4%. According to Rappai and Fvosenfed (1935) the R.Q. of ftyperthyroid rats was not affected by vitamin A. Smith and Perman (1940) maintained that carotene did not affect the R.Q. of cats injected with thyroxine for 3 days. This information suggests that vitamin A did not affect the metabolism of any particular diet. Chevalier and Baert (1934) found that excess vitamin A decreases the metabolic rate below normal. However, no affect of vitamin A on oxygen consumption of normal rats was found by various authors such as Sherwood, et a l . (1934), Belasco and Murlin (1940) and Sheets and Struck (1942). Rappai and Rosenfed (1935) found that B.M.R. was lowered in rats given vitamin A by 4 to 12%. These studies indicate that the simultaneous administration of thyroxine and vitamin A w i l l prevent the rise in oxygen consumption to the level produced by thyroxine alone. The thyroid gland, and in turn the metabolic rate, may be influenced by the amount of vitamin A mobilized from the liver reserves. This - 6 -aspect is therefore considered. Johnson and Baumann (1947) found that after ingestion of carotene, li v e r storage of vitamin A is depressed in hyperthyroidism. They found no influence of preformed vitamin A on the thyroid gland. A similar finding was reported by Chanda, et.al. (1952) with cows and goats, and also by Cama and Goodwin (1949) with rats. On the other hand, working with rats, Arnrich and and Morgan (1954) and Wiese et a l . (1948) found that carotene and vitamin A are equally well uti l i z e d by normal and hypothyroid rats. According to Arnrich and Morgan (1954) the difference in storage of vitamin A was due to a reduction in growth of the hypothyroid rats. Ascarelli, et a l . (1964) found that thyroxine-fed chicks showed increased vitamin A storage and that this effect was dependent on vitamin A and thyroxine levels in the diet. Nir and Ascarelli (1966) reported that vitamin A depletion from the l i v e r was increased by thyroxine administration. The percentage of vitamin A palmitate in the l i v e r was also found to be increased. Thiouracil was shown to produce the opposite effect. Johnson and Baumann (1947) showed that liver depletion of vitamin A dependent only ^ " upon the basal metabolic rate,,: also upon the growth rate. They found that restricting growth had a more pronounced effect on retarding the depletion of liver vitamin A than increasing thyroid activity which increased the depletion of vitamin A. Phillips CL962) demonstrated that changing environmental temperatures had no affect on hepatic storage and the rate of metabolism - 7 -of orally administered retinyl acetate. His results indicated that prolonged exposure to cold did not increase the vitamin A requirement. These results however are in contrast with those reported by Ershoff (1950) who observed a decreased survival time of vitamin A ' deficient rats at low environmental temperatures (3°C). Ershoff concluded that the vitamin A requirement was increased by prolonged exposure to cold. In subsequent studies Ershoff, (1952) fed graded levels of retinyl palmitate and observed a resistance to low environmental temperatures. He reported that an average daily intake of 0.9 mg of retinyl palmitate was adequate for growth and survival at room temperature but inadequate at 2°C. Porter, and Masora (1961) demonstrated that cold-acclimated rats stored less vitamin A in the l i v e r . than rats acclimated at 25°C. These rats were fed a diet low in vitamin A with weekly supplementation of vitamin A. Saunderson, et a l . (1967) found that the extent of liver vitamin A storage remained unchanged at 5°C from that observed at 25°C. They found however that the weight gain in rats at 5° was always less than that at 25°C. Increased vitamin A depletion ration in 4-week cold-exposed rats was abolished by 0.1% thiouracil in the diet. The reduced survival times of vitamin A deficient rats exposed to cold indicated an increased requirement for vitamin A in the cold. It was found that at least 20 times more retinoic acid was necessary to maintain growth and survival in the cold at 5°C. Seelers and You (1950) found that exposure of rats to 5°C causes a two-fold increase in metabolic rate. It can be expected that these rats would have had a greater depletion of vitamin A than the controls at 25°C. - 8 -Differences in temperature (Saunderson, et a l . (1967)) and thyroid function have been implicated in affecting the maturation of the gonads (Ball, (I960)). Vitamin A may be involved in the temperature-thyroid-gonad interrelationship. Weslau et a l . (1938) and Poumea-Delille (1943) reported hypertrophy of the reproductive organs in hypervitaminotic A rats. Maslov (1960) and Roussel et a l . (1963) found that the daily addition of carotene or vitamin A supplements to mature bulls resulted in a significant increase in semen volume, concentration, and v i t a l i t y of spermatozoa. De Vuyst et a l . (1958) and Zelfel (1961) found that weekly administration of large doses of vitamin A improved the f e r t i l i t y in the a r t i f i c i a l l y inseminated cow. Maddock, et a l . (1953) observed that long continued injection of moderate doses of vitamin A in young weaned rats e l i c i t e d degenerative lesions in the testes but lesions did not deyelop in mature rats. Biswas and Deb (1965) reported excess -yitamin A can cause s t e r i l i t y in rats. Biswas and Mukhesji (1968) •reported that testicular activity had been inhibited in hypervitaminotic -rats. These workers suggested that testicular damage was due to a lack of hypohyseal gonadotropin in hypervitaminotic rats. Much literature has been published on the effects of an excess of vitamin A. These studies began with the assumption that the symptoms of an excess of vitamin A might exaggerate the normal mode of action. The mode of action of vitamin A on metabolism remains unanswered. This investigation was undertaken to study the possible effects of excess vitamin A and, in addition, the effect on reproduction in the chicken. - 9 -This investigation takes the form of three parts. Part I deals with the effect of an excess amount of vitamin A on the rate of hatch. Vermes et a l . (1939) found that eggs of well nourished hens contained 300-800 IU of vitamin A each. In order to control the level of vitamin A present in the egg, the eggs are injected with vary-ing levels of vitamin A and in two different forms. The rate of hatch of treated eggs is observed directly. In Part II a study of dietary vitamin A palmitate on thyroid gland is made. There is evidence of an antagonism between vitamin A and thyroxine, which has been noted from the effects of vitamin A status on the size and histological condition of the thyroid gland. These changes have been reported to occur in vitamin A deficiency and in an excess of vitamin A (Sherwood, et a l . (1934); Mitzkewitsch (1934); Uotila (1938). Finally, Part III is an appraisal of thyroid interrelationship with vitamin A. In this study thyroid activity i s evaluated by different methods u t i l i z i n g a variety of parameters such as respiration rate, thyroid weight, muscle tempera-ture, and radioiodine uptake and release by the thyroid gland. - 10 -PART I EFFECT OF HYPERVITAMINOSIS A ON INCUBATION TIME Experimental New Hampshire hens of a closed f l o c k since 1953 were rai s e d i n f l o o r pens. These birds had been on a standard layer d i e t . The eggs used f o r a l l the h a t c h a b i l i t y experiments were c o l l e c t e d from these hens. Eggs were c o l l e c t e d over a 7 day period p r i o r to incubation and were stored i n a cool room. The eggs were subjected to a pre-incubation treatment of i n j e c t i o n s of vitamin A palmitate and c a r r i e r o i l . To prevent d e t e r i o r a t i o n of vitamin A the c a r r i e r o i l was deaerated under vacuum and the vacuum released with nitrogen. P r i o r to i n j e c t i o n each egg was swabbed with 70% ethanol. A dentist's d r i l l was. used to d r i l l a t i n y hole i n the blunt end of the egg. Using a #27 gauge needle 5/8 inch long for i n j e c t i o n into the albumin and (#26 gauge 1 inch long needle f o r i n j e c t i o n s i n t o the yolk) a tuberculin syringe, 0.1 ml/egg of treated and untreated o i l was i n j e c t e d . The hole was sealed with adhesive tape. The eggs were incubated immediate i n pre-warmed trays of a Jamesway incubator. On the 19th day of incubation the eggs were transfered into hatching trays. At noted i n t e r v a l s , the number of hatched chicks were counted. - 11 -Preliminary Experiment A preliminary experiment was desirable to become acquainted with the injection procedure and to determine treatment level effect on hatchability. Thirty eggs per treatment were injected as follows; 30 eggs with no injection, 30 eggs with carrier o i l (corn o i l ) only, 30 eggs with 2,000 IU vitamin A palmitate, 30 eggs with 4,000 IU vitamin A palmitate, and 30 eggs with 8,000 IU vitamin A. A l l 150 eggs were placed in a single tray i n the incubator. On the 19th day of incubation the eggs were transfered into hatching trays. At noted intervals the number of chicks hatched were counted. Five chicks from each treatment were sacrificed and the livers quickly removed into chilled tared beakers. These livers were freeze-dried overnight. The pooled, freeze-dried and weighed livers were ground into a fine powder and dispensed into 40 ml extraction tubes. The livers were then extracted with 30-60° fraction petroleum ether. The solvent was evaporated using vacuum d i s t i l l a t i o n and nitrogen. The residue was then saponified according to Neff et a l . (1949) and Dugan, et a l . (1964). The f i n a l vitamin A fraction was evaporated to dryness under vacuum, nitrogen and dissolved to a 50 ml volume with chloroform. A 1.5 ml aliquot was taken and to i t was added 1.5 ml of trifluoroacetic acid. The optical density of the reaction mixture was read immediately at 616 my using a Beckman B spectrophotometer. Experiment #1 The preliminary experiment indicated that vitamin A palmitate may have prolonged incubation time. To confirm this observation an experiment - 12 -was set up using a larger number of eggs. The highest level (8,000 IU per egg) of vitamin A from the preliminary experiment was chosen as the treatment since the lower levels did not appreciably affect incubation time. In addition, a small preliminary experiment was conducted to determine i f vitamin A injected into the yolk would have a different effect than vitamin A injected into the albumin. The manipulation and treatment of eggs were as previously described. Experiment #2 This experiment was designed to study the effect of vitamin A alcohol on the rate of hatchability. Preincubation treatment of 360 eggs per treatment was carried out as previously described. Control eggs were injected with 0.1 ml per egg of carrier o i l , soyabean o i l . Test eggs were injected with 0.1 ml per egg containing 8,080 units vitamin A alcohol in soyabean o i l . The hatching trays were spatially alternated in the incubator. In this way f u l l trays would permit a uniform incubation environment. On the 19th day of incubation the eggs were candled and a l l the i n f e r t i l e eggs and ead embryos were removed and recorded. After hatching the chicks were examined morphologically for growth defects or abnormal behavior. This experiment indicated that a level of 8,080 units vitamin A per egg was highly toxic to the-chick embryo Experiment //3 Experiment 3 was designed to induce a treatment effect without using toxic levels. Two levels were chosen, 1,070 units and 3,160 units vitamin A per egg; 277 eggs per level were injected. For control eggs, 166 eggs were injected with carrier o i l , corn o i l . - 13 -Results and Discussion The preliminary experiment using 2,000 IU, 4,000 IU and 8,000 IU of vitamin A palmitate indicated that vitamin A palmitate retarded hatching: (Table 2). The results of the preliminary experiment made i t imperative to repeat this experiment using the highest level of vitamin A palmitate and employing a larger number of eggs. >The results of the preliminary experiment were confirmed (Table 2). It i s interesting to note that vitamin A is reported to have a retarding effect in metamorphosis. McCarrison (1943) reported that cod l i v e r o i l retarded metamorphosis of tadpoles. Rakhlina (1936) observed that carotene had a similar effect on axolotls, and Eufinger and Gotlleih (1935) found that administration of vitamin A to tadpoles depressed the metamorphosis-accelerating action of thyroxine. Since the egg contains vitamin A largely i n the alcohol form ^ (Neff, et a l . (1949); Parrish, et al". (1950)) vitamin A alcohol, was also studied for i t s effect on the rate of hatchability. In experiment number 3, the results demonstrated that a dose of 8,080 IU/ egg resulted in high embryonic mortality in the early stages of develop-ment. The embryos that died i n the second and third week of incubation showedhemorrhages. To reduce the toxic effect, the treatment was lowered to levels of 1,070 IU and 3,160 IU vitamin A alcohol per egg to demonstrate a treatment effect. In both levels of vitamin A alcohol the treatment effect resulted in hemorrhages in the embryo of the late second and third week stage. Dingle and Lucy (1962) have demonstrated, in vitro, that excess retinal caused increased permeability of erythrocyte membranes and suggested that vitamin A controls membrane permeability. These - 14 -results were confirmed by Kinsky (1963). Dingle and Lucy (1962) suggest that the i n i t i a l mode of action i s one of penetration and expansion of the cells membrane. A similar action could take place on the embryonic red cells and on the vascular system by altering i t s el a s t i c i t y , consequently resulting in embryonic death due to hemorrhaging. Apart from the direct action of vitamin A on the embryonic vascular system, a f a l l in the blood concentration of the thyroid hormone and i t s resultant effects must be considered. Langman and Fanssen (1955) succeeded in producing malformations of the eye, cleft palate, and harelip in the rat embryo by performing partial thyroidectomy or by inducing hypothyroid state in the mother. Hodge, et a l . (1952) and Eliphinstone (1953) report that hypothyroidism of the mother may cause the congenital malformation of her child. The author has found gross abnormalities which included cross beaks, abnormally shaped head, one eye opened a l l in each of three embryos from the higher level of vitamin A alcohol. In a d d i t i o n o n e of the three embryos the intestines were outside the body cavity. The lower level of vitamin A alcohol had only one embryo with an underdeveloped head, without an upper beak and one eye opened and malformed. These abnormalities are similar to those observed by Fern (1967) in the hamster which included exencephaly, microphthalmia, l i p and palate cle f t s , after administration of vitamin A. Similar defects were observed in the rat by Cohlan (1934) ', Giroud and Martinet (1959) ', and in the swine by Palludon (1966). Fujita, et a l . (1970) induced fetal exencephaly by hypervitaminosis A i n pregnant rats. Forty-one percent of a l l implanted embryos had exencephaly, - 15 -some had spina b i f i d a , open eyes, and microstomia. The thyroid glands of the l i v i n g fetuses were examined h i s t o l o g i c a l l y and compared with the non-exencephaly group. The exencephaly group showed co n s i s t e n t l y s l i g h t l y lower f o l l i c u l a r c e l l height. In a l l of the present experiments mortality was highest i n the less than one week group. This suggests that vitamin A has an e f f e c t at a s p e c i f i c stage i n morphogenesis. These r e s u l t s are s i m i l a r to those of Thompson, (1969), who found that at very early stages a f t e r 5 days incubation embryonic mortality increased with increase i n i n j e c t i o n dose of up to 500 ug/egg of r e t i n o i c acid and 1000 ug/egg of r e t i n o l . Vitamin A i n the egg yolk i s predominantly i n the alcohol form regard-le s s of the form fed or the l e v e l of supplementation. The content of vitamin A alcohol i n i n d i v i d u a l eggs ranges from 71-93% of the t o t a l vitamin A (Neff et a l . (1949)). Analysis for vitamin A i n the l i v e r s of newly hatched chicks showed that the vitamin A content increases with increase i n administered dose. Presumably a maximum dosage i s reached at 4,000 IU of vitamin A palmitate since an increase to 8,000 IU indicates a decrease i n l i v e r vitamin A (Table 3). The i n j e c t i o n into the egg of the alcohol form did not appreciably change the content of the l i v e r vitamin A i n the hatched chicks. I t has been suggested that vitamin A alcohol ( r e t i n o l ) may be stored i n the parenchymal c e l l s complexed with protein whereas the r e t i n y l esters are stored i n the Kupffer c e l l s (Glover and Morten, 1948; Ganguly, 1960). Post-absorptive blood vitamin A consists l a r g e l y of r e t i n o l rather than r e t i n y l esters. In the present experiment the m o b i l i z a t i o n of l i v e r esters i s not f u l l y understood. It i s not c e r t a i n where exactly the r e t i n y l esters from the l i v e r are hydrolyzed and i t i s possible that more than one process may be involved. 'The i n t e s t i n a l mucosa contain many enzyme systems and i f vitamin A can act as an i n h i b i t o r i t would be t o x i c . Bears and cats have-large l i v e r stores of r e t i n y l esters. I t may be that the r e t i n y l esters are - 16 -not toxic and that free retinol must be under the action of hydrolase enzymes. On the:j:other hand the vitamin A. alcohol toxicity may have an effect on membranes. Dingle and Lucy (1962) have observed that addition of vitamin A to sus-pensions of erythrocytes from various species causes rapid c e l l l y s i s . The embryos subjected to vitamin A alcohol treatment i n the present experiment showed hemorrhaging. It is not unlikely that vitamin A alcohol, in entering a membrane brings about abnormal stretching of the l i p i d moiety and the integrity of the l i p i d protein structure i s adversely affected. Glavert, Daniel, Lucy and Dingle (1963) demonstrated in electron micrograph studies of rabbit erythrocytes that vitamin A alcohol increases the surface area until vaculoles are formed resulting in'.hemolysis thereafter. A destructive effect of vitamin A alcohol on membranes may be a secondary effect when present i n high concentration; a primary effect of the vitamin appears on the endocrine system. The results of the present experiment demonstrate a retardation i n the rate of hatch with both the ester and alcohol form of vitamin A. Oxygen consumption is increased i n vitamin A deficiency and the adminis-tration of thyroxine accelerates oxygen comsumption whereas thiouracil delays oxygen consumption as well as the vitamin A deficiency syndrome. Coma and Goodwin (1949) reported that the excretion of carotene in feces was enhanced by administration of thiouracil and reduced by thyroid in rats. Similar results were reported by Chanda, Clapham, McNaught and Owen (1951). Subsequent experiments by Chanda and Owen (1952) showed that thyroxine increased and thiouracil decreased the carotene and vitamin A content in cow's milk. The results of the present experiment indicates that vitamin A, both ester and alcohol have a primary effect on the endocrine system. A secondary effect of vitamin A appears to be on the membrane. - 17 -Table 1. Mortality of embryos in vitamin A injected eggs Treatment No. of dead embryos at stages of development Infertile 1 week 1-2 weeks 2-3 weeks No. of chicks No. of eggs Preliminary Experiment no injection 1 corn o i l 6 2,000 IU vitamin A 4 palmitate 4,000 IU vitamin A 3 palmitate 8,000 IU vitamin A 4 palmitate Experiment #1 corn o i l 20 8,000 IU vitamin A 28 palmitate corn o i l (yolk 3 injection) 8,000 IU vitamin A 3 palmitate (yolk inj ection) Experiment #2 soya bean o i l 139 8,080-IU vitamin A 160 alcohol Experiment #3 corn o i l 63 1,070 IU vitamin A 120 alcohol 3,160 IU vitamin A 80 alcohol 1 4 4 1 1 19 24 8 3 30 139 63 93 10 9 1 2 19 13 7 3 2 3 5 5 2 16 14 36 21 12 18 15 26 17 17 21 21 95 85 8 8 136 27 82 72 86 30 30 30 30 30 160 160 20 20 360 360 166 277 277 - 18 -Table 2. Rate of hatchability % of total hatch at 20-21st day over the total hatch at 22nd day Treatment 27 32 42 47 % of total hatch 50 53 56 76 90 hours Preliminary Experiment no injection corn o i l 2,000 IU vitamin A palmitate 4,000 IU vitamin A palmitate 8,000 IU vitamin A palmitate Experiment #1 corn o i l 8,000 IU vitamin A palmitate Experiment #3 corn o i l 1,070 IU vitamin A alcohol 3,160 IU vitamin A alcohol 4 - - 73 - - 92 6 - - 82 94 65 - - 88 - 76 - - 90 - 62 - 90 1 44 60 75 2 - 39 48 54 61 73 81 89 92 40 60 71 88 93 46 60 68 78 85 100 97 95 Table 3. Analysis of vitamin A in livers of newly hatched chicks Treatment Vitamin A in li v e r in units/gm dry weight no injection 192. 44 + 6.18 corn o i l 185. 55 + 21.63 soyabean o i l 183. 58 + 49.24 2,000IU vitamin A palmitate 248.96 + 6.33 4,000 IU vitamin A palmitate 518. 78 + 7.89 8,000 IU vitamin A palmitate 447. 78 + 68.92 1,070 IU vitamin A alcohol 212. 46 + 3.97 3,160 JD vitamin A alcohol 218. 25 + 10.25 8,080 IU vitamin A alcohol 232. 04 + 3.61 - 19 -PART II EFFECT OF HYPERVITAMINOSIS A ON THYROID ACTIVITY -HISTOLOGICAL ASSESSMENT Experimental Experiment #1 Adult White Leghorn female chickens were used. 294 birds were divided into 98 birds per treatment i n r e p l i c a t e s of 2 groups of 49 bir d s each. They were housed i n i n d i v i d u a l laying cages. Feed and water were supplied ad l i b i t u m . The control birds were fed a standard basal d i e t containing 4,400.IU vitamin A palmitate/kgm of d i e t . The test birds were fed two d i f f e r e n t l e v e l s of vitamin A (Rovi-mix A-325,000 IU/gm). Birds on treatment #2 received an a d d i t i o n a l 200,000 units of vitamin A palmitate/kgm of d i e t . Birds on treatment #3 received an a d d i t i o n a l 400,000 units/kgm of d i e t . At the termination of the test 6 birds from each treatment were k i l l e d . The thyroids were removed immediately and placed i n Bouin's f i x a t i v e . The thyroid glands were embedded i n wax. S e r i a l sections of 8 .u were prepared and subjected to Harris hematoxylin and eosin. The thyroid glands from birds on treatment diets no. 2 and no. 3 were studied m i c r o s c o p i c a l l y and compared with control treatment no. 1. A general observation of several f i e l d s per section indicated a treatment d i f f e r e n c e . In order to quantitate the differ e n c e an estimate - 20 -of the ratio of epithelial tissue to colloid in each thyroid gland was made in the following manner. The thyroid gland section was visually bisected at the vertical axis across the gland. The fo l i c l e s on the bisecting line were measured for f o l l i c l e diameter over a known distance. The sum total of the areas was substracted from the total distance, thus obtaining the ratio of epithelial tissue to colloid. The use of the ratio of colloid to epithelial tissue per f i e l d for each bird gives a more sentitive indication than thyroid weight of thyroid activity. Experiment #2 Four-week-old White Leghorn, male, birds were used. The chicks had previously been fed a standard chick starting diet. They were housed in individual cages at room temperature. Feed and water were supplied ad libitum. The composition of the basal diet i s shown in Table 13 of the appendix. The dietary treatment of test birds were formulated by supplementing the basal diet with 400,000 IU vitamin A palmitate/kgm of feed. The birds were kept on treatment diet for 4 weeks. At termination of the experiment the birds were k i l l e d and the thyroid glands were treated as described in experiment 1. - 21 -Experiment #3 Twenty-four adult, male, Japanese quail were used. They were housed in individual cages in two environment chambers. These chambers were thermostatically controlled at 14-15°C and 22-23°C respectively. Feed and water were given ad libitum. The composition of the all-mash quail diet i s shown in Table 14. The dietary treatments of the two rations was formulated by supplementing the basal diet with two levels of vitamin A palmitate. Ration #1 contained 2,000 IU of vitamin A palmitate/kgm of feed. Ration #2 contained, 200,000 IU of vitamin A palmitate/kgm of feed. Six birds were subjected to each of the experimental treatments of 2 different temperatures and 2 different levels of vitamin A. At the termination of this experiment the quail were k i l l e d . The l e f t thyroid gland was quickly removed and fixed in Zenker's acetic acid solution for histological examination. The slides were studied as described in experiment 1. Results and Discussion According to Tala (1953) the percentage of epithelium in adult animals might be considered as a measure of thyroid function, the amount of epithelium being increased together with the function. Conversely in the hypofunctioning gland the amount of epithelium is - 22 -decreasing and the amount of colloid i s increasing. In experiment 1 a l l control birds showed f o l l i c l e s containing colloid quantities within normal limits which were somewhat evenly distributed throughout the gland. Of the six hens on 200,000 units vitamin A per kgm of feed, 4 showed a marked increased in f o l l i c u l a r size and hence colloid. The remaining two hens showed only a tendency toward an increase in f o l l i c u l a r size. The increase in colloid size (Table 4) may reflect a hypofunctioning gland due to a depressed metabolic rate resulting from a decrease in TSH. Similar results were reported by Schneider (1934) and Fellinger and Hochstaedt(1936). The increased supplementation of the diet with vitamin A palmitate did not influence thyroid size. This is in agreement with Dua et a l . (1968). These workers found no alteration in thyroid size from vitamin A treatment. This is contrary to results of studies using the rat (Sadhu, et al.. ; (1947)) where a decrease in thyroid size occurred in response to an excess of vitamin A. In contrast to the reported results and those of the present experiment are the reports made by Carpenter and Sampson (1956). These workers fed toxic overdosages of vitamin A to rats. Histological studies demonstrated f o l l i c l e s containing small amounts of colloid, which were reduced in size and irregular in shape. The f o l l i c u l a r cells were hypertrophied. Hypervitaminosis A and vitamin A deficiency have been known to have similar effects. In vitamin A deficiency Coplan and Sampson (1935) found that the thyroid gland was hypertrophied in female rats, but atrophied in male rats. In experiment 2 histological studies of thyroid gland from each of the 10 cockerels on basal diet showed a normal proportion of epithelial tissue to colloid (Fig. 3). The overall picture was typical with l i t t l e individual variation. On the other hand, the cockerels treated with 400,000 IU vitamin A per kgm of diet, demonstrated an increase in f o l l i c u l a r size. The overall proportion of colloid was greater than control glands (Fig. 4). A measured estimate of percent colloid was significantly different from control at 1 and 5% level of significance. Epithelial cells were cuboidal in shape with no marked indication of regression. It would appear that there may be a general depression of secretion of thyroid stimulating hormone, in response to vitamin A treatment. In experiment 3, the quail fed the control diet at 14SC responded to the cold as expected. It is known that the metabolic rates of birds decreases when ambient temperatures are elevated (Huston- et a l . (1962)). On the other hand, a bird exposed to cold w i l l increase i t s metabolic rate and depress i t s heat loss mechanisms. Thyroid activity increases in response to release of thyroid stimulating hormone. Microscopic studies of thyroid glands indicated that this was the case in the present experiment. The thyroid glands of quail fed the basal diet and kept at 14°C were relatively lower in colloid content 68.7%, and with a slight increase in epithelial c e l l depth compared with the quail fed the basal diet and kept at 22°C, (Table 7, Fig. 6 ). Quail treated with an excess of vitamin A palmitate and kept at 14°C were relatiyely higher in colloid content, (75.2%) , than the thyroid glands of birds kept on basal diet at 22°C (68.3%), but they were no s t a t i s t i c a l l y significant. This reflects a neutralizing effect. While 0 - 24 -the lower temperature of 14°C tends to Increase the metabolic rate, the high level of vitamin A tends to lower the metabolic rate and increase the sensitivity to the cold. According to Dua et a l . C1968) the effects of an excess of vitamin A are similar to those of thiouracil. Thiouracil renders an animal hypothyroid and reduces the metabolic rate (Sulman and Perek, 1947; Romijn, 1950; McCartney and Shaffner, 1950; Mellen, 1958). Iifethe present experiment, the treatment of the quail with a high level of vitamin A and at 14°C, the ambient tempera-ture counteracts the vitamin A effect by raising the body metabolism. This i s supported by the ration X temperature interaction which is s t a t i s t i c a l l y significant at 1% level (Table 7). Treatment with excess vitamin A palmitate at 22°C did not give the expected picture. Two glands from this treatment show a mixed population of large and small f o l l i c l e s in about an equal proportion. The remaining four glands have a uniform population of small f o l l i c l e s with the exception of one of these glands which has a few large f o l l i c l e s at the periphery. It appears that histological measurements are inadequate in the evaluation of thyroid function for the above treatment effect. Other indices of thyroid activity are necessary to evaluate the effect of an excess of vitamin A at 22°C in the Japanese quail. The s t a t i s t i c a l analysis for the present and subsequent experiments is found tabled in the appendix. - 25 -Table 4. Effect of vitamin A palmitate on the activity of the thyroid gland as indicated by % colloid in the thyroid gland, in the female chicken Treatment Mean % Colloid Standard in the thyroid deviation gland Basal diet 82.2 3.406 200,000 IU vitamin A per 95.4 1.612 kgm basal diet 400,000 IU vitamin A per 89.3 3.606 kgm basal diet Table 5. Result of Duncans multiple range test for % epithelial tissue in thyroid gland" Treatment 2 3 4.56 10.75 17,7 Mean values sharing the same line are not significantly different at 5% level 1(* - 26 -Table 6. Effect of vitamin A palmitate on the activity of the thyroid gland as indicated by % colloid in the thyroid gland, of the male chicken \ ^ Treatment Mean % Standard Colloid Deviation Basal diet 56.9 3.036 400,000 -EI vitamin A per 63.5 2.112 kgm diet Table 7. Effect of vitamin A palmitate and temperature on the activity of the thyroid gland in the Japanese quail Treatment Mean % Standard Colloid Deviation Basal diet at 14 C 68.7 5.283 Basal diet at 22 C 74.2 2.319 200,000 IUvitamin A per 75.2 4.456 kgm basal diet at 14 C 200,000 IUvitamin A per 68.3 6.935 kgm basal diet at 22 C - 27 -Figure 1: Thyroid gland of a White Leghorn female Chicken on a di e t containing a normal l e v e l of vitamin A. 575X. Figure 2: Thyroid gland of a White Leghorn female chicken on a diet containing 200,000 IU vitamin A per kgm basal d i e t . 575X. - 28 -Figure 3: Thyroid gland of a White Leghorn female chicken on a diet containing 400,000 IU vitamin A per kgm basal diet. 575X. - 29 -Figure 4: Thyroid gland of a White Leghorn male chicken on a diet containing a normal l e v e l of vitamin A. 575X. Figure 5: Thyroid gland of a White Leghorn male chicken on a diet containing 400,000 IU of vitamin A per kgm basal d i e t . 575X. - 30 -Experiment 1 Experiment 2 Experiment 3 Experimental treatment diets with added vitamin A palmitate and at different temperatures ure 6: Histogram showing colloid present in thyroid glands of the female and male chicken and the male CcjuaXb respectively in three separate experiments. These birds were on normal and excess vitamin A diet and at different temperatures. - 31 -PART III EFFECT OF HYPERVITAMINOSIS A ON THYROIDAL UPTAKE AND RELEASE OF IODINE Experimental Experiment 1 Two hundred day-old male White Leghorn chicks were randomly distributed into compartments of 20 birds each. Five replicate lots (a total of 100 birds) were placed on each treatment. The chicks were watered and fed ad libitum. The composition of the basal diet is shown in Table 15. The control birds received basal ration only whereas the test birds received 400,000 IU of vitamin A palmitate per kgm basal diet. At the end of 5 weeks the birds were weighed and a population of 120 birds, 60 birds per treatment of an average 131 body weight, were selected for I . These birds were r e d i s t r i -buted into 5 compartments per treatment of 12 birds each. At zero - 32 -time a group of 8 of the 12 birds per compartment were injected 131 intravenously with 0.25 y c i l as Nal. At 6, 10, 24, 48, and 96 hours after injection, the birds were weighed and k i l l e d . The thyroid glands were removed and weighed. Radioactivity of the glands was measured in a well-type s c i n t i l l a t i o n counter. From the remaining 40 birds per treatment from the treated population described in experiment 1, 30 were used for xygen consumption studies. A small animal respirometer, Warren E. Collins, Inc., was employed. The birds were starved for 24 hours in an environment chamber set at 23°C in which the studies were carried out. Breast muscle temperatures were measured. The combs and gonads were removed and weighed. The gonads were immediately fixed in 10% buffered formal saline for histological studies. Experiment 2 Two hundred day-old White Leghorn chicks were randomly distributed into compartments of 20 birds each. Five replicate lots (a total of 100 birds) were placed on each treatment. The chicks were watered and fed ad_ libitum. The composition of the basal diet i s shown in Table 15. The control birds received the basal ration only, whereas the test birds received a basal ration supplemented with 400,000 IU of vitamin A palmitate per kgm diet. - 33 -At the end of 5 weeks the birds were weighed and a population of 120 birds, 60 birds per treatment of an average body weight, were selected 131 for uptake of I . These birds were redistributed into 5 compartments per treatment of 12 birds each. At zero time a group of 8 of the 12 131 birds per compartment were injected intravenously with 0.25 ^uci I as Nal. At 6, 10, 24, 48, and 96 hours after injection the birds were weighed and k i l l e d . The thyroid glands were removed and weighed. Radioactivity of the glands was measured in a well-type s c i n t i l l a t i o n counter. Twenty birds per treatment from the remaining 40 birds were k i l l e d and their adrenal glands removed and weighed. Results The data in Tables 17 and 18, Figs. 7 and 8 indicate that there was a highly significant difference in iodine uptake by the glands of the control birds and those fed excess vitamin A after 6 hours. Maximum uptake in the latter was at a level of 14.15% compared with the control group which was only 10.29% of the administered dose. After 10 hours, the uptake in the vitamin A treated group was relatively higher than the control group but the difference was not significant. 131 The hypervitaminotic birds showed a more rapid release of I from the thyroid than did the control birds. Thyroidal radioactivity declined to 6.30% of the injected dose in the hypervitaminotic birds compared 131 with 7.96% in the control birds after 96 hours. Uptake of I per mg thyroid weight indicated a relative increase after 6 hours in the - 34 -vitamin A treated birds but this difference was not significant from the control group. Unlike the results in experiment 1(Table.8&9) the data from experiment 2 indicated a reduction in thyroid activity in response to excess intake 131 of vitamin A. I n i t i a l uptake of I both as a % per mg thyroid weight and as a % administered dose showed a highly significant difference between the hypervitaminotic birds and the control group (Table 19 and 20, Fig.9&10 ). In the control group the maximum uptake was 18.58%. After 96 hours radioactivity declined to 9.34% of administered dose. Although there was no difference in body weights between treatments there was a significant difference in the thyroid weights per 100 gm body weight in both experiments (Table 10). There was a decrease i n testes and comb weight, however (Table 23). Each difference in average weight of these was s t a t i s t i c a l l y significant at the 5% lev e l . Oxygen consumption was not s t a t i s t i c a l l y different in the treated birds from those in the control group. The breast muscle temperature was relatively lower in the birds treated with an excess of vitamin A. With a decline in breast muscle temperature there appears to be a decline in testes weight and also a suppression in spermatogenesis (Table 11). Histological changes in testes based on microscopic studies indicate a marked difference in degree of differentiation. Five of the 16 birds treated with an excess of vitamin A show a retardation in maturation. This i s indicated by a large amount of i n t e r s t i t i a l tissue, a moderate number of primary spermatocytes and some secondary spermatocytes. Only one bird from the treated groups showed testes - 35 -with large seminiferous tubules and the spermatocytes in this instance advanced to the secondary stage. Seminiferous tubules were small in the treated birds compared with the control group. The control birds showed testes with an advanced stage of maturation. Testes in these birds contained a moderate amount of i n t e r s t i t i a l tissue with spermatocytes at the secondary stage, with some mature cells ranging to very l i t t l e i n t e r s t i t i a l tissue with mature ce l l s , spermatids and spermatozoa (Fig. 11 & 12). Only one of the six samples showed a very large amount of i n t e r s t i t i a l tissue with, primary and secondary spermatocytes. There was an average decrease of 25% in the size of the testes in the birds treated with an excess of vitamin A. The heaviest of these was most advanced in spermatogenesis while the lightest of these was least advanced in spermatogenesis. In addition to the reduced comb weight, there was a loss of turgidity and normal bright coloring. Although there were hot significant differences between the average body weights, the adrenal weights were s t a t i s t i c a l l y significant (Table 22). The birds treated with an excess of vitamin A had adrenals which were increased in weight (Table 12). 131 Table 8 : Mean Thyroid Weights and I Uptake Values for Control and Treated Birds (S.D.) i n Experiment 1. Hours a f t e r i n j e c t i o n 6 10 24 48 96 Radioiodine uptake % of administered dose control 10.29 ± 2.35 12.82 ± 3.33 14.24 ± 1.76 13.31 ± 2.45 7.96 ± 1.37 excess vitamin A 14.12 ± 2.26 15.06 ± 4.17 14.60 ± 1.67 11.16 ± 3.15 6.30 ± 1.70 Radioiodine" uptake % control .458 ± .13 .633 ± .07 .575 ± .01 .560 ± .03 .266 ± .008 of administered dose/mg of thyroid excess vitamin A .585 ± .254 .587 ± .14 .531 ± . 04 .445 ± .06 .206 ± .082 Thyroid weight mg control 23.62 ± 6.07 20.73 ± 5.05 24.90 ± 5.07 23.66 ± 2.48 29.65 ± 4.23 excess vitamin A 25.80 ± 7.15 25.62 ± 2.98 27.73 ± 3.30 24.93 ± 4.75 30.95 ± 6.70 Thyroid weight mg/100 gms control 5.87 ± 1.23 5.42 ± 1.13 6.32 ± 1.05 5.41 ± .55 5.92 + .97 body weight excess vitamin A 6.38 ± 1.54 6.05 ± 2.99 6.99 ± 3.39 5.78 ± .71 6.42 ± 1.20 131 Table 9 : Mean Thyroid Weights and I Uptake Values for Control and Treated Birds (S.D.) in Experiment 2, hours treatment 10 24 48 96 Radioiodine uptake % control 9.43 ± 2.19 18.38 ± 4.55 14.64 ± 3.66 13.31 ± 2.04 9.34 ± 2.12 of administered dose excess vitamin A 8.36 ± 1.21 15.05 ± 3.53 13.41 ± 3.67 13.00 ± 1.58 13.15 + 3.49 Radioiodine uptake % control .44 ± .083 .75 + .093 .57 ± .102 .43 ± .218 .31 ± .086 of administered dose per mg thyroid weight excess vitamin A .36 ± .067 .57 ± .136 .50 ± .087 .44 ± .086 .36 ± .096 Thyroid weight mg control 21.6 excess vitamin A 24.2 24.6 27.1 25.7 29.5 31.6 30.8 31.1 38.5 Thyroid weight control 5.06 ± 1.10 6.13 ± 1.60 6.17 ± .60 7.11 ± 1.05 6.36 ± .95 mg/100 gms body weight excess vitamin A 5.99 ± 1.64 6.38 ± 1.43 7.24 ± 1.32 7.19 ± 1.53 7.98 ± 1.06 — 38 -Table 10: Effect of Vitamin A on the Mean Body Weight, 0^ Consumption, Temperature, Testes and Comb Weight in Chicks in Experiment 1. Treatment Body weight Thyroid weight 0^ Consumption/hr/gm gms mg %/100 gm body weight body weight Control 429.6 ± 16.67 5.79 ± 1.02 1.22 ± .32 Vitamin A 430.3 ± 16.36 6.63 ± 1.05 1.27 ± .29 Treatment Breast muscle Testes %/gm Comb %/gm body weight temperature 0 C body weight Control 42.88 ± .34 45.30 ± 23.74 0.97 ± .30 Vitamin A 42.65 ± .45 30.94 ± 11.00 0.66 ± .38 Table 11: The Relationship Between Testes Weight, Degree of Differentia-tion and Breast Muscle Temperature Testes degree of breast muscle mg % per differentiation temperature °C 100 gm body weight Control 55.82 41.94 34.23 32.46 27.02 29.02 Ave. value 35.35 ± 10.63 Excess vitamin A 37.24 32.42 24.12 23.88 21.98 19.58 26.56 ± 6.8 3 2 2 3 1 2 43.3 43.0 43.1 43.0 42.9 43.0 2.1 43.05 ± 0.141 3 1 1 1 1 1 42.7 42.6 42.8 42.9 42.3 42.3 1.3 42.6 ± 0.255 - 39 -Table 12: Effect of an Excess of Vitamin A on the Mean Thyroid, Adrenal, and Body Weights of Chicks in Experiment 2. control S.D. Vitamin A S.D. Thyroid weight mg %/100 gms 6.28 ± 0.8118 6.94 ± 1.507 body weight Adrenal weight mg %/100 gms 10.18 ± 1.865 12.10 ± 1.311 body weight . • ii Body weight gms 433 ± 36.74 430 ± 34.50 20 CD w o 'a • a) n-cu 4-1 ca •H C • •rf I. CO 4-) o a; cd 4-1 P. CD a-•H o •rl O •H-T) Cd Figure 7 16 12 0 — r 45 60~ —r-75 — i — 90 ° 1 5 3 0 -*•> ou io. 90 105 Hours after injection of I . Thyroidal uptake and release of radioiodine in chicks fed normal and excessive levels of vitamin m experiment 1. The vertical lines indicate the S.D. of each m e a n ^ J^ls vitamin 1.0 6 0 • H OJ X ) • K O >> 6 0 js CU AS 4-J 0) c • H T3 O • H O • H 13 Pi normal excess vitamin A — r — 15 30 — i — 45 60 r131 — r -75 —r~ 90 105 Figure 8: Hours after injection of I" Thyroidal uptake and release of radioiodine in chicks fed normal and excessive levels of vitamin A in experiment 1. The vertical lines indicate the S.D. of each mean T » 1 1 r 1 : 1 1 0 15 30 45 60 , 75 90 105 Hours after injection of I Figure 9: Thyroidal uptake and release of radioiodine in chicks fed normal and excessive levels of vitamin A in experiment 2. The vertical lines indicate the S.D. of the mean. 1.0 0 0 •r-i CD o u >> rZ • 6 0 e cu 4J Pi •3 . ro 0.8 0.6 0.4 H 0.2 1 normal '. . excess of vitamin A 131 Figure 10: 0 15 Hours after injection of I Thyroidal uptake and release of radioiodine in chicks fed normal and excessive levels of vitamin A in experiment 2. The vertical lines indicate the S.D. of each mean. 105 - 44 -Figure 11: Testes from White Leghorn male chicken on a diet contain-ing a normal level of vitamin A. Testes show normal spermatogenesis. O ~m 4 iff* 2 Figure 12: Testes from White Leghorn male chicken on a diet containing an excess of vitamin A. Testes show a noticeable proliferation of interstitium, small seminiferous tubules either at a resting state or slow maturation. - 45 -Discussion The data obtained indicate that hypervitaminosis A may have an effect upon the activity of the thyroid gland. A reduction in thyroid stimulating hormone (TSH) by vitamin A treated rats was suggested by Sadhu and Truscott (1948). Observations typical of a hyperactive thyroid gland: loss of colloid, reduction of size of f o l l i c l e s irregularity in outline of f o l l i c l e s and increase in height of f o l l i c u l a r epithelium were reported by Sherwood et a l . (1934) who fed an excess of vitamin A to rats. Similar histological changes were reported by Sherwood et a l . (1935); Uotila (1938); Wegelin, (1939). Carpenter and Sampson (1956) reported that the uptake of radioiodine by the thyroid gland was increased in rats fed an excess of vitamin A. In agreement with the latter investigators are the results in the present study in experiment 1. Experiment 2 gave the reverse effect. The results of experiment 1 may be a consequence of nervous stress, trauma or tempera-ture change in transit. Although the transport of the birds during the winter from the main laboratory battery cages to the farm battery cages was brief, i t may have been a contributing factor since this was the only obvious change in the handling of birds which differed from experiment 2. The birds may have been undergoing recovery from the change at which time the radioiodine was injected. A reversal of thyroid activity was reported by March et a l . (1966) as a consequence of moving the birds to an unheated room which resulted in an alteration of the metabolic rate and a subsequent shift in the blood hemolysis curve. The reversal was explained as a response to temperature change. In experiment 2, of the present study, the birds were maintained in the same environment throughout the experiment. The effect of vitamin A in experiment 2 indicates a decline in thyroid activity. This i s in agreement with results obtained by Lutsyuk (1961) who reported that rats fed an excess of vitamin A showed a significant increase in the weight of their thyroid gland and a decrease in the absolute quantity of iodine in the gland. THe found that by the addition of a thyroid antagonist to the diet of rats fed a deficient, normal and an excess level of vitamin A, there was a decrease in the concentration of iodine in the thyroid which was most marked in the rats fed an excess of vitamin A. Frap et a l . (1959) reported that in both vitamin A deficiency and an excess intake resulted in a reduction of thyroxine secretion in the pig. A decrease in basal metabolism in the rat as a result of an excess of vitamin A was reported by Farmand (1960); Veil et a l . (1961); Sadhu et a l (1947); and Chevalier and Baert (1934). The simultaneous administration of thyroxine and vitamin A resulted in a decease in oxygen consumption in the rat (Rappai et a l . (1935); Abelin (1935)) and in the cat by Smith and Perman Q.940) . It is interesting:' to find that contradictory results of the effect of an excess of vitamin A are reported in the literature and that both of these opposing effects have been obtained in the present study. There are other factors that could contribute to the variation from one experiment to another. * Apart from environmental temperature there are such factors as genetic strain, age, and dietary 131 intake of iodine. The time peak of I uptake can be influenced by iodine concentration in the diet (Kobayashi and Gorhman (1960) and Rosenburg (1964). A low iodine diet resulted in a rapid f a l l of - 47 radioactivity after reaching a peak at 6 hours (Kobayashi and Gorbman (I960)). The increase in the enlargement of the gland which was shown to be s t a t i s t i c a l l y significant in both experiments may be due to an increase in colloid production with a subsequent enlargement i n the f o l l i c l e s , as has been observed in histological studies of the earlier experiments. Oxygen Consumption It has been noted that inspite of the histological results contradictory results regarding the oxygen consumption have been reported in the rat. A decrease in oxygen consumption in rats fed a daily dose of 50 IU/gram body weight was reported by Chevallier and Baert (1934); Abelin (1934); Logaras and Drummond (1938) and Belasco and Murlin (1940). The latter workers reported no effect of vitamin A on oxygen consumption. Similar findings were reported by Sherwood et a l . (1934); Sadhu and Brody (1947); and Sheets and Struck (1942). In the present experiment there was no significant difference in oxygen consumption between the birds fed excess vitamin A and the birds fed the control diet. Breast muscle temperature There was a significant difference in breast muscle temperature between the 6 birds per treatment. While these birds showed a difference in degree of differentiation in the testes, there was only a relative difference in the muscle temperature. Unpublished data in our laboratory have shown a significant increase in breast muscle tempera-ture in hens on a prolonged excess intake of vitamin A. It appears that the length of time on the excess vitamin A treatment could be an - 48-important factor in addition to age and sex of test animal and-the resulting "effect on the metabolism. Adrenal weights Adrenal weight has been used as a measure of adrenocortical function. An increase in adrenal weight is found in stimulation of adrenocortical function accompanied by a decrease in cholesterol and ascorbic acid level (Sayers (1950)). The increase in adrenal weight in the present experiment is in agreement with the findings of Singh et a l . (1969) that the administration of an excess of vitamin A to rats led to an increase in adrenal weight. An increase in adrenal weight in rats fed an excess of vitamin A was also reported by Ames et a l . (1952); (1954). Testes and comb'development The present experiment shows that the retarded testes development as reflected in weight and histological picture may be due to a general increase in thyroid activity. According to Wilwerth et a l . (1954) feeding of desiccated thyroid in heavy dosages depresses testes development in the male fowl under 12 weeks old. - 49 -SUMMARY A study was made on the interrelation between thyroid function and excess vitamin A in avian metabolism. The study took the form of three parts. Fir s t a histological assessment was made of the effects of hypervitaminosis A on the thyroid activity. Quail were fed normal and excess levels of vitamin-A and kept at controlled temperatures of 14° and 22°C. The birds fed the normal level of vitamin showed greater thyroid activity at 14°' than at 22° C, whereas histological appearance of the thyroid glands of the birds fed the excess vitamin A indicated similar activity at the two temperatures. Thyroid activity in quail fed excess vitamin A and kept at 22°C was greater than in quail fed a normal level of vitamin A at this temperature. Secondly, the effect of hypervitaminosis A on the incubation time of chicken eggs was studied. Pre-incubation injection of both vitamin A palmitate or alcohol into eggs prolonged the incubation time compared with that of control eggs. Thirdly, a study of the effect of hypervitaminosis A on the thyroidal uptake and release of radioiodine was made. In two Separate experiments the data obtained indicate that hypervitaminosis A respectively decreased and increased thyroid activity. It is apparent both from these observations and from evidence in the literature that the effect of excess vitamin A on thyroid activity interacts with unidentified components of the environment. Although there was no difference in oxygen consumption, hypervitamin-osis does affect the endocrine system. This effect i s indicated by an - 50 -increase in the size of the thyroid and adrenal gland and a decrease in the size of the testes and combs in birds fed an excess of vitamin A. - 51 -REFERENCES Abbott U.K. and V.S. Asmundson, 1957. Scaleless and inherited ectodermal defect in the domestic fowl. J. of Heredity, 48: 63. Abelin, I. 1953. Ztschr. f. physiol. chem. 217: 109 Cited after D r i l l , V.A. (1943). Aberle, S.D. and W. Landauer, 1935. Thyroid weight and sex in newly hatched chicks. Anat. Rec. 62: 331. Ames, S.R., W.J. Swanson, H.A. Risley and P.L. Harris, 1952. Hyper-vitaminosis A induced by crystalline vitamin A acetate. Fed. Proc. 11: 181. Ames, S.R., W.J. Swanson, H.A. Risley and P.L. Harris, 1954. Vitamin A. aldehydes metabolism, biopotency and toxicity. Fed. Proc. 13: 174. Arnrich, L. and A.F. Morgan, 1954. The u t i l i z a t i o n of carotene by hypothyroid rats: J. Nutr. 54: 107. Ascarelli, I., P. Budowski, I. Nir and A. Bondi, 1964. The influence of thyroid status on the u t i l i z a t i o n of vitamin A and carotene by chickens. Poult. Sci. 43: 310. Bal l , J.N., I960. Reproduction in female boney fishes. Symp. Zool. Soc. London 1: 105. Bates, R.W., 0. Riddle and E.L. Lahr, 1941. A strain difference in responsiveness of chick thyroids to thyrotropin and a step-wide increase during three years in thyroid weights of Carneau pigeons. Endocrinology 29: 492. Benedict, F.G., W. Landauer, and E.L. Fox, 1932. The physiology of normal and f r i z z l e fowl, with special reference to basal metabolism. Storrs Agricultural Experimental Station Bull. 177. Belasco, I.J. and J.R. Murlin, 1940. The effect of vitamins A and C on experimental hyperthyroidism. J. Nutr. 20: 577. Biswas, N.M. and M. Mukherji, 1968. Effect of excess vitamin A on pituitary gonadal axis in rats. Anat. Anz. 123: 337. Boelum, J. 1948, Vitamin A requirement of laying pullets, o f f i c i a l report. Eight world's Poultry Congress, Copenhagen. Cama, H.R. and T.W. Goodwin, 1949. Studies in vitamin A. IX. Role of the thyroid in carotene and vitamin A metabolism. Biochem. J. 45: 236. Cama, H.R. and T.W. Goddwin, 1949. Studies in vitamin A 13. Alleged formation of vitamin A from 3-carotene treated with iodinated casein. Biochem. J. 45: 317. - 52 -Carpenter, E., and M.M. Sampson, 1956. The effect on excess vitamin A in the diet on the thyroid gland of young female albino rats. Anat. Rec. 124: 391. Chanda, R., N.M. Clapham, M.L. McNaught and E.C. Owen, 1952. The dig e s t i b i l i t y of carotene by the cow and the goat as affected by thyroxine and thiouracil. Biochem. J. 50: 95. Chevalier, A. and H. Baert, 1934. De 1'influence de l a vitamine A sur le-metabolisme du rat et du cobaye. Compt. Rend. Soc. Biol. 116: 1037. Cohlan, S.Q., 1934. '-Congenital anomalies in the rat produced by excessive intake of vitamin A during pregnancy. Pediatrics 13: 556. Cooper, D., March B. and J. Biely, 1950. The effect of feeding thyroprotein and thiouracil on the vitamin A requirement of the chick. Endocrin. 46: 404. Caplan, Hl.M. and M.M. Sampson, 1935. The effects of a deficiency of iodine and vitamin A on the thyroid gland of the albino rat. J. 'Nutr. 9: 469. DeVuyst, A., L. Henriet and C. Meeus, 1958. Vitamin A et f e r t i l i t e . Ann. Med. Ve't. 102: 304. Dingle, J.T. and J.A. Lucy, 1962. Studies on the mode of action of excess vitamin A. Biochem. J. 84: 611. D r i l l , V.A., 1934. Interrelations between thyroid function and vitamin metabolism. Physiol. Rev. 23: 355. Dua, P.N., V.L. Dubai, E.J. Day and J.E. H i l l , 1968. Influence of different forms of vitamin A thyroxine, and thiouracil on carotenoid u t i l i z a t i o n by chicks. Proc. Soc. Exptl. Biol. Med. 128: 262. Dugan, R.E., N.A. Frigerio and J.M. Siebert, 1964. Calorimetric determina-tion of vitamin A and i t s derivatives with trifluoroacetic acid. Analytical Chemistry 36: 114. Eliphinstone, N. 1953. Thiouracil in pregnancy. Lancet i : 1281. Eufinger, H. and J. Gottlieb, 1933. Klin Wchnschr 12: 1397. Cited after D r i l l , V.A. 1934. Physiol. Rev. 23: 355. Ershoff, B.H., 1950. Effects of prolonged exposure to cold on the vitamin A requirement of the rat. Proc. Soc. Exp. Biol. Med. 74:586. Ershoff, B.H., 1952. Effects of vitamin A malnutriture on resistance to stress. Proc. Soc. Exp. Soc. Exp. Biol. Med., 79: 580. - 53 -Fellinger, K. and 0. Hochstaedt, 1936. Wien Klin. Wchnschr. 49:1339. Cited after D r i l l , V.A., 1934. Physiol. Rev. 23: 355. Ferm, V.H. 1967. Potentiation of teratogenic effect of vitamin A with exposure to low environmental temperature. Life Sci. 6: 493. Farmand, H., 1960. Metabolisme peripherique de la thyroxine chez le rat en hypervitaminose A. Academie des Sciences. Comptes Rendus 250: 3055. Frap, D.L., V.C. Speer, V.W. Hays, D.V. Catron, 1959. Thyroid function in the young pig and i t s relationship with vitamin A. J. Nutr. 68: 333-341. Fujita, T., Y. Eguchi, Y. Morikowa and Y. Hashimoto, 1970. Hypathalamic-hypophysial adrenal and thyroidal systems: observations in fetal rats subjected to hypothalamic destruction, brain compression and hypervitaminosis A. Anatomical Record, 166: 659. Funk, E.M., 1936. Factors influencing hatchability i n the domestic fowl. Missouri Agricultural Experimental Station Bulletin 341. Ganguly, J., 1960. Absorption, transport and storage of vitamin A. Vitamins Hormones 18: 387. Giround, A., D.Gouelle et M. Maritinet, 1957. Donnees quantitatives sur le taux de l a vitamin A chez le rat lors d'experiences de teratogenese par hypervitaminose A. Bull. Soc. Chem. bi o l . Paris 39: 331. Glover, J., T.W. Goodwin and R.A. Morton 1948. Studies in vitamin A. 6. Conversion in vivo of vitamin A aldehyde to vitamin A. Biochem. J. 43: 109. Hodge, R.R., H.E. Hamilton and W.C. Keetal, 1952. Pregnancy Myxedema. Arch. Intern. Med. 90: 863. Hollander, W.F. and 0. Riddle, 1946. Goiter in domestic pigeons. Poult. Sci. 25: 20. Huang, H.S. and D.S. Goodman, 1965. Vitamin A and carotenoids 1. Intestinal absorption and metabolism of l^c-labelled vitamin A alcohol and g-carotene in the rat. J. Biol. Chem. 240: 2839. Hutt, F.B., 1930. The genetics of the fowl 1. The inheritance of the frizzled plumage. J. Genetics 22: 109. Huston, T.M., T.E. Cotton, and J.L. Caron, 1962. The influence of high environmental temperature on oxygen consumption of mature domestic fowl. Poult. Sci. 41: 179. - 54 -Johnson, R.M. and CA. Baumann, 1947. The effect of thyroid on the conversion of carotene into vitamin A. J. Biol. Chem. 171: 513. Johnson, R.M. and CA. Baumann, 1948. Relative significance of growth and metabolic rate upon the u t i l i z a t i o n of vitamin A by the rat. J. Nutr. 35: 703. Kinsky, S.C. 1963. Comparative responses of mammalian erythrocytes and microbial protoplasts to polyene antibiotics and vitamin A. Arch. Biochem. 102: 180. Kobayashi, E. and A. Gorbman, I960. Radioiodine u t i l i z a t i o n i n the chick. Endocrinol. 66: 795. Kachhar, D.M. 1967. Teratogenic activity of retinoic acid. Acta Pathol. Microbial. Scand., 70: 398. Landauer, W., 1942. Form and function in f r i z z l e fowl: the interactions of hereditary potentialities and environmental temperature. Biological Symposium 6: 127. Landauer, W. and L.C Dunn, 1930. The "Frizzle" character of fowls. J. of Heredity 21: 291. Landauer, W., 1949. The hatchability of chicken eggs as influenced by environment and hereidty. Storrs >Agric. Expt. Sta. Bull. 262, p. 7. Landauer, W., 1946. The results of selection against expression of the short upper beak mutation in fowl. Amer. Nat. 80: 490. Langman, J. and F. Faasen., 1955. Congenital defects in the rat embryo. American J. Opthal 40: 6576. Lewis, H.R. and W.C Thompson, 1915. Report on the poultry husbandman. Thi r t y - f i f t h annual report of the New Jersy State Agriculture Experimental Station for the year ending Oct. 1914, p. 99. Lissot, G. et F. Caridroit, 1941. Role de la vitamin A dans l a faculte d'eclusion des oeufs. Bulletin de l a Societe de chimie Biologique 23: 201. Lutsyuk, N.B., 1961. Vopr. Pitaniya 20: 40. Cited In: The Vitamins edited by W.H. Sobrell and R.H. Harris, New York. Academic Vol. 1, 1967, p. 211. Maddock, C.L., J. Cohen and S.B. Wolbach, 1953. Effect of hypervitaminosis A on the testes of the rat. A.M.A. Arch. Path. 56: 333. March, B.E., V. Coates and J. Biely, 1966. Interacting effects of thyroid activity and dietary level of vitamin A on erythrocyte f r a g i l i t y in the chicken. Canadian J. Physiol, and Pharm. 44: 295. - 55 -Maslov, N.F. 1960. The effect of vitamin A on semen production in bulls. Zivotnovodstvo 22:39. Cited after D r i l l , V.A. (1943). McCartney, M.G., and C.S. Shaffner, 1948 (University of Maryland, College Park). Paper presented at 37th annual meeting of Poultry Science Association. (Abstract). McCartney, M.G., and C.S. Shaffner, 1949. Chick thyroid size and incubation period as influenced by thyroxine, thiouracil, and thyroprotein. Poult. Sci. 28: 223. McCartney, M.G. and C.S. Shaffner, 1950. The influence of altered metabolism upon f e r t i l i t y and hatchability in the female fowl. Poult. Sci. 29: 67. McCarrison, 1930. J. Med. Res., 18: 577, Cited after D r i l l , V.A. (1943). Mellen, W.J., and B.C. Wentworth, 1958. Studies with thyroxine and t r i -iodothyroxine in chickens. Poult. Sci. 37: 1226. Mitzkewitsch, M.S'. Arch. Exper. Path. und. Pharmakol 174: 339. 1934. Cited after D r i l l , V.A. (1934). Morgan, A.F.and C.E. White, 1950. Utilization of carotene and vitamin A by hyperthyroid and pregnant rats. American Dietetic Association J. 26: 569. Mussehl, F.E. and P. Bancroft, 1924. Effect of low temperature on hatching power of hen's eggs. Poult. Sci. 4: 79. Neff, A.W., D.B. Parrish, J.S. Hughes and L.F. Payne, 1949. The state of vitamin A in the.eggs. Arch, of Biochem. 21: 315. Nir, I. and I. Ascarelli, 1966. Effect of dietary protein level and thyroxine on vitamin A depletion from liver in chicks. British J. Nutr. 20: 41. Parrish, D.B., R.N. Williams, J.S. Hughes and L.F. Payne, 1947. Transfer of vitamin A from the yolk to the chick during incubation. Arch. Biochem. 29: 1. Paumeau-Delille, G., 1943. Compt. Rend. Soc. Biol. 137: 373. Cited after Biswas, N.M. and C. Deb, 1965. Endokrinologie 49: 64. P h i l l i p s , W.E.J., 1962. Low temperature environment stress and the metabolism of vitamin A in the rat. Can. J. Biochem, Physiol. 40: 491. Porter, E., and E.J. Masora, 1961. Effect of cold acclimation on vitamin A metabolism. Proc. Soc. Exp. Biol. Med. 108: 609. - 56 -Rand, C.G., M.S. Riggs and M.B. Talbot, 1952. The influence of environmental temperature on the metabolism of the thyroid hormone in the rat. Endocrinol 51: 562. Rappai, S., and P. Rosenfed, 1935. Pfluger's Arch. 236: 464. Cited after D r i l l , V.A. (1943). Riddle, 0. 1930. Carnegie Institution of Washington Yearbook 25: 55. Rokhlina, M.L. 1936. Bull. Biol. Med. Exp. U.R.S.S. 2: 219. Cited after D r i l l , V.A. (1943). Romijn, C. 1950. Stofwisselingsonderzolk bij de kip. Proeven met Voord-Hollandse Blaviven. Tijdschr. Diergenlesk 75: 839, Cited after P.D. Sturkie, Avian Physiology, Comstock Publ. Association Ithaca, New York, 1965. p. 610. Rosenburg, L.L., M. Goldman, G. La Roche and M.K. Dinsick, 1964. Thyroid function in rats and chickens. Equilibration of injected iodine with existing thyroidal iodine in Long Evans rats and White Leghorn chickens. Endocrinol. 74: 212. Rubin, M. and N.R. Bird, 1942. Relation of vitamin A to egg production and hatchability. Maryland Agricultural Experiment Station Bulletin A12. Sadhu, D.P. and S.-'Brody, 1947. Excess vitamin A ingestion, thyroid size and energy metabolism. The Am. J. Physiol. 149: 400. Sadhu, D.P., and B.L. Truscott, 1948. Hypervitaminosis A and the distribution of body iodine. Enocrinol. 43: 120. Saunderson, P.R., V.G. Winters, and D.G. Therriault, 1967. Effect of low envirnomental temperature on the metabolism of vitamin A (retinol} in the rat. J. Nutr. 92: 474. Sayers, G. 1950. The adrenal cortex and homeostatis. Physiol. Rev. 30: 241. Schneider, E. Deutsch. Ztschr. f. chir. 1934, 242: 189. Cited after D r i l l , V.A. (1943). Sellers, E.A. and S.S. You, 1950. Role of the thyroid in metabolic responses to a cold environment. Am. J. Physiol. 163: 81. Sheets, R.F. and H.C. Struck, 1942. Vitamin A and the thyroid. Science 96: 408. Sherwood, T.C. and W.G. Luckner, 1935. Further studies on the effect of cod liver o i l on the thyroid gland. J. Nutr. 9: 123. - 57 -Sherwood, T.C., L.A. Toth, K.D. Karr, 1924. Effects of cod-liver o i l on basal metabolism and on the thyroid gland. Endocrinol 18: 254. Singh, V.N. M., Singh, T.A. Bemkitasubramanian, 1969. Early effects of feeding excess vitamin A: Mechanism of fatty l i v e r production in rats. J. Lipid Res. 10: 395. Smith, D.C. and J.M. Perman, 1940. Effect of thyroxine combined with carotene upon the oxygen consumption of cats. Endocrinol. 27: 110. Smyth, J.R., 1954. Hairy, a gene causing abnormal plumage in the turkey. J. Heredity 45: 197. Sulman, F. and M. Perek, 1947. Influence of thiouracil on the basal metabolic rate and on molting in hens. Endocrinol. 41: 514. Tala, P. 1953. Comparison of the.epithelial percent and nuclear volume determination'as indicators of thyroid activity following stimulation by TSH. Endocrinol. 53: 474. Taylor, M.W., J.R. Stern, W.C. Russell and E. Jungherr. 1947. The pro vitamin requirement of hens. Poult. Sci. 26: 243. Temperton, H. and F.J. Dudley, 1947. The effects of using preformed vitamin A as a sole dietary source of vitamin A for growing chcickens and adult fowls. Harper Adams U t i l i t y Poultry Journal 32, N.S. No. 4, p. 1-28. Thompson, J.N. 1969, Vitamins i n development of the embryo. The Am. J. Clin. Nutr. 22: 1063. Thompson, J.N., M. McHowell, G.A.J. Pitts and C.I. Houghton, 1965. Biological activity of retinoic acid ester in the domestic fowl: Production of vitamin A deficiency in the early chick embryo. Nature 205: 1006. Thompson, J.N. and G.A.J. P i t t , 1960. Vitamin A acid and hypervitaminosis A. Nature 188: 672. Ukita, T. 1919. Acta scholae Medical University imp. in Kioto 3: 287. Cited after D r i l l , V.A. (1943). Uotila, U. 1938. Ulber die Schilddriisen Veranderungen b l i A, B, C, D. avitaminosen. Virchow's Arch. 301: 535. Cited after D r i l l , V.A. (1943). Vei l , C , E. Triantaphyllides and N. Farmand, 1961. Pathol. Biol. Semaine Hop. [N.S.] 9: 2285. In: The vitamins- edited by W.H. Spbrell and R.H. Harris. New York, Academic Vol. 1, 1967, p. 212. Vickers, G.S., 1936. A. hatchability study among Ohio hatcheries. Poult. Sci. 15: 496. Vermes M., P. Meunier and Y. Raoul, 1939. Sur la faible accumulation de l a vitamine A dans l'oeuf de Poule et dans le foie de Poussin. Acad, des Sciences. Comptes Rendus 209: 578. - 58 -Warren, D.C., 1934. The influence of some factors on the hatchability of the hen's egg. Kansas Agricultural Experiment Station Technical Bulletin, 37. Wegelin, C., 1939. On the antagonism^, between thyroxine and vitamin A Western J. Surg. Obstet. "Gyn. 47: 147. Weslau, W., B. Wrohski, A. Wroblewski and B. Wroblewski, 1938. Klin Worhrchr 17: 777. Cited after Biswas, N.M. and C. Deb (1965). Endocrinologie 49: 64. Wheeler, R.S. and E. Hoffman, 1948. Influence of quantitative thyroprotein treatment of hens on length of incubation period and thyroid size of chicks. Endocrinol. 43: 430. Wiese, C.E., J.M. Mehl, and H.J. Deuel, 1948. Studies on carotenoid metabolism IX. Conversion of carotene to vitamin A in the hypothyroid rat. J. Biol. Chem. 175: 21. Wilwerth, A.M., C. Martinez-Campos, and E.P. Reineke, 1954. Influence of the thyroid status on volume and concentration of cock semen. Poult. Sci. 33: 729. Zelf e l , S. 1961. The effect on semen quality and f e r t i l i t y of feeding kelpan and wheat germ as a supplement to bulls used for a r t i f i c i a l insemination. Tierzucht 15: 128. - 59 -APPENDIX - 60 -Table 13: Composition of the basal diet for White Leghorn male chickens Component % wheat 47.0 oats 15.0 barley 20.0 soyabean meal 10.0 d i s t i l l e r s solubles 2.0 dehydrated cereal grass 2.0 iodized salt 0.5 bonemeal 2.5 limestone 1.0 gifts/kgm manganese sulphate 12.54 vitamin A palmitate C325,000 lU/gm) 1.0342 vitamin D3 C20,000 ICU/gm) 2.2 riboflavin - 25% activity 6.248 amprol - 25% (coccidiostat) 49.94 - 61 -Table 14: Composition of the all-mash quail diet. Component % ground wheat 25.0 ground corn 25.0 soyabean meal 35.5 herring meal 5.0 vegetable o i l 2.0 d i s t i l l e r s solubles 2 .0 dehydrated cereal grass 2 .0 bonemeal 2 .0 limestone 1.0 iodized salt 0.5 gms/kgm manganese sulphate 35.2 vitamin D 3 C20,000 ICU/gm 2.2 Vitamin A C325,000 IU/gm) 1.344 - 62 -Table 15: Composition of the basal diet of chickens in the thyroidal uptake and release studies Component % wheat 67.5 soyabean meal 25.0 d i s t i l l e r s solubles 2.0 dehydrated cereal grass 2.0 bonemeal 2.0 limestone 2.0 iodized salt 0.5 mg/kgm manganese sulfate 149.0 riboflavin 3.96 calcium pantothenate 9.42 niacin 22.0 choline chloride 264.0 amprol -.25% 499.0 -yitamin 436.1 ICU vitamin A palmitate 4400.0 IU vitamin E as a-tocopheryl acetate 275.0 IU - 63 -Table 16: Analysis of variance of the % c o l l o i d i n the thyroid gland. In the female chicken: ss df MS To t a l 1192.90 17 Treatment 524.76 1 524.76 Error 668.14 16 41.75 In the male chicken: ss df MS Tot a l 420.85 19 Treatment 267.80 1 267.8 Error 153.05 18 8.50 In the male Japanese q u a i l : ss df MS Total 741.72 23 Ration 0.70 1 0.70 Temperature 2.67 1 2.67 Ration x Temperature 234.04 1 234.04 Error 506.97 20 25.34 s i g n i f i c a n t at 1% - 64 -131 Table 17: Analysis of variance of I uptake % of total dose Sources of variance ss df MS 6 hours Total Treatment Error 133.0657 58.1401 74.9256 15 1 14 58.1401 10.86** 5.3518 10 hours Total Treatment Error 232.4170 20.1810 212.2360 15 1 14 20.181 15.150 1.33 24 hours Total Treatment Error 41.8576 0.0598 41.7978 15 1 14 0.0598 2.9845 0.02 48 hours Total Treatment Error 130.699 19.109 111.590 15 1 14 19.1090 7.9707 2.39. 96 hours Total Treatment Error 45.8388 11.0889 34.749 15 1 14 11.0889 2.48 4.47 - 65 -131 Table 18: Analysis of variance of I uptake % per mg of thyroid weight Source of variance ss df MS 6 hours T o t a l Treatment E r r o r .447 ,064 ,383 15 1 14 ,064 ,027 2.37 10 hours T o t a l Treatment E r r o r ,290758 ,008234 ,282524 15 1 14 .0082 .0202 ,0004 24 hours T o t a l Treatment E r r o r ,0568 .0074 .0494 15 1 14 ,0074 ,0035 2.11 48 hours T o t a l Treatment E r r o r .14116 ,05312 ,08804 15 1 14 .053 ,022 2.41 96 hours T o t a l Treatment E r r o r ,0346 ,01531 .01928 15 1 14 ,015 ,0013 11.12** - 66 -Table 19: Analysis of Variance of I Uptake % of Administered Dose in Experiment 2. Source of variance ss 6 and 10 hours Total 815.19 Treatment 38.76 Time 489.06 Error 287.37 24 hours Total 188.302 Treatment .047 Error 188.255 48 hours Total 47.317 Treatment .381 Error 47.046 96 hours Total 150.12 Treatment 32.63 Error 117.49 df MS F 3 1 1 38.76 3.9 ^ 1 489.06 49.35 29 9.90 15 1 .047 .003 14 13.44 15 1 .381 .113 14 3.36 15 1 32.63 .388 14 83.92 - 67 -131 Table 20: Analysis of Variance of I Uptake % per mg of Thyroid Weight in Experiment 2. Source of variance ss df MS 6 and 10 hours Total Treatment Time Error .8641 ,1417 .5330 ,1894 31 1 1 29 ,1417 ,5330 ,0065 21.8 82.0' 24 hours Total Treatment Error ,1470 ,0196 ,1274 15 1 14 .0196 ,0091 2.15 48 hours Total Treatment Error ,0981 ,0004. ,0977 15 1 14 ,0004 ,0068 0.058 96 hours Total Treatment Error .1236 ,0056 .1180 15 1 14 .0056 .0084 0.66 - 68 -Table 21,: Analysis of variance Source of variation Body weight SS df MS F Total 21282 79 Treatment 10 1 10 0.0367 Error 21272 78 272 Source of variation Breast muscle temperature °C ss df MS F Total 5.58 33 Treatment .45 1 .45 2.81 Error 5.13 32 .16 Source of variation O2 consumption/hr/gm body we ight" ss df MS F Total 5.36 59 Treatment .02 1 .027 0.296 Error 5.34 58 .091 Source of variation Thyroid weight mg %/gm body weight ss df MS F Total 89.51 79 Treatment 5.68 1 5.680 5.28* Error 83.83 78 1.075 Source of variation Testes %/gm body weight ss df MS F Total 12667.46 33 Treatment 1745.32 1 1745.3 5.1* Error 10922.14 32 341.3 Source of variation Comb %/gm body weight ss df MS F Total 4.52 33 Treatment .81 1 .816 7.049* Error 3.71 32 .115 - 69 -Tabiefv22>: Analysis of 'Va:r.iaii'ce}iiif.Qr the Thyroid, Adrenal" aha^Body Weignt ' .* for WL Chickens'1 t^eatie'd with'an, .Excess of Vitamin A':and i' ., ' -•• •''>s- ^.••:,i--v.'»-.'-'v;fuvw«;- Compared with WL Chickens on a Normal Level df'Vitamin A. Source of Variation ss df MS F Thyroid gland weight mg %/gm body weight Total 162.36 79 Treatment 12.06 1 12.06 Error 150.30 78 1.92 Adrenal weight mg %/gm body weight Total 135.26 39 Treatment 36.36 . 1 36.36 Error 98.90 38 2.60 Body weight, gms • Total 105.461 79 Treatment '•588. 1 588 Error 104873r 78 1344.5 6.28 ; 13.98. 0.00043 Viona Coates June 1971 Interacting Effects of Thyroid Activity and Dietary Level of Vitamin A on Erythrocyte Fragility in the Chicken. B. E. March, V. Coates and J. Biely. 1966. Canadian Journal of Physiology and Pharmacology 44: 295-300. Effects of Estrogen and Androgen on Osmotic Fragility of Fatty Acid Composition of Erythrocytes in the Chicken. B. E. March, V. Coates and J. Biely. 1966. Canadian Journal of Physiology and Pharmacology 44: 379-387. Reticulocyte Counts in the Chicken. B. E. March and V. Coates. 1966. Poultry Science 45: 1302-1305. The Erythropoietic Response in Chickens with Inherited Muscular Dystrophy. B. E. March, V. Coates and J. Biely. 1966. Proc. of the Society for Experimental Biology and Medicine 122: 1126-29. The Effect of Fishmeal Supplementation of Breeder Rations on Hatcha-bilit y . B. E. March, J. Biely, C. Goudie and V. Coates. 1967. Poultry Science 46: 1532-1536. The Influence of Diet on Toxicity of the Antioxidant 1,2,Dihydro-6-Ethoxy-2,2,4-Trimethylquinoline. B. E. March, J. Biely and V. Coates. 1968. Canadian Journal of Physiology and Pharmacology 46: 145-149. Respiration Rate of Muscle Mitochondria from Genetically Dystrophic Chickens. B. E. March, J. Biely and V. Coates. Proc. Society for Experimental Biology and Medicine 129: 566-568. Reticulocytosis in Response to Dietary Antioxidants. 1969. B. E. March, J. Biely and V. Coates. Science 164: 1393-1400. Thyroxine-binding by Muscle Mitochondria fron Normal and Genetically Dystrophic Chickens. B. E. March, JI Biely and V. Coates.' 1969. Proc. Society for Experimental Biology and Medicine 132: 345-347. 

Cite

Citation Scheme:

        

Citations by CSL (citeproc-js)

Usage Statistics

Share

Embed

Customize your widget with the following options, then copy and paste the code below into the HTML of your page to embed this item in your website.
                        
                            <div id="ubcOpenCollectionsWidgetDisplay">
                            <script id="ubcOpenCollectionsWidget"
                            src="{[{embed.src}]}"
                            data-item="{[{embed.item}]}"
                            data-collection="{[{embed.collection}]}"
                            data-metadata="{[{embed.showMetadata}]}"
                            data-width="{[{embed.width}]}"
                            async >
                            </script>
                            </div>
                        
                    
IIIF logo Our image viewer uses the IIIF 2.0 standard. To load this item in other compatible viewers, use this url:
http://iiif.library.ubc.ca/presentation/dsp.831.1-0101798/manifest

Comment

Related Items