UBC Theses and Dissertations
Effect of maternal dietary deprivation in rats on growth and development of progeny Toews, Judith Gay
Reports in the literature indicate that maternal dietary deprivation during pregnancy and lactation can influence the growth and development of progeny. While the offspring often suffer permanent growth impairment, it is sometimes possible for restricted progeny to catch-up in size to normal age-mates following a period of accelerated growth. In 1964, Chow and Lee reported growth hormone-induced catch-up growth in weight of offspring of restricted rats. An animal experiment was designed in order to study the effects of maternal undernutrition on skeletal growth and development of offspring. A secondary purpose of the study was to ascertain whether catch-up in skeletal dimensions could be stimulated by the administration of growth hormone. Sprague Dawley rats were maintained on Purina Laboratory Chow throughout pregnancy and lactation with restricted animals receiving approximately 50 percent of the amount consumed by ad libitum fed controls. Male offspring comprised 6 treatment groups: progeny of restricted mothers which were given growth hormone injections early in postnatal life, later in postnatal life, or not at all; and progeny of controls which were given early injections of growth hormone, later growth hormone injections, or no growth hormone. Offspring were weaned at 49 days post-copulation and fed ad libitum for one year. At regular intervals they were weighed, measured for body, and tail length, and X-rayed to permit assessment of skeletal growth and maturation. Results indicate that the progeny of restricted dams suffered growth retardation and a temporary delay in skeletal maturation. Restricted offspring had normal proportions but were permanently stunted in size. No differences among groups were found for either the restricted or control offspring indicating that exogenous growth hormone was ineffective in permitting restricted progeny to catch-up to controls with respect to weight, length, or skeletal dimensions. Therefore, if there is a connection between the growth impairment of restricted progeny and pituitary insufficiency, the relationship must be complex. A model is proposed in order to suggest possible inter relationships between growth hormone status and growth impairment of offspring of dams restricted in diet during pregnancy and lactation.
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