Purification of a neuropeptide from the corpus cardiacum of the desert locust which influences ileal transport
department or school: Science, Faculty of
department or school: Zoology, Department of
data provider: DSpace
degree campus: UBCV
creator: Audsley, Neil
issued: 2011-01-25T19:16:26Z
issued: 1991
related degree: Doctor of Philosophy - PhD
degree grantor: University of British Columbia
description: Previous studies on the regulation of salt and water reabsorption in the insect excretory system have concentrated on the rectum, while regulation of the ileum has received little attention. Cl⁻ transport is the predominant ion transport process in both the ileum and rectum of the desert locust and drives fluid absorption. The central nervous system (CNS) was surveyed for factors which stimulate Cl⁻-dependent short-circuit current (I[formula omitted]) using in vitro flat sheet preparations of locust ileum as a bioassay. All ganglia extracts tested (except the corpora allata) caused significant increases in ileal I[formula omitted]. Extracts of muscle tissue, used as a control, had no effect on ileal I[formula omitted] indicating that stimulants were not general metabolites present in locust tissue. Crude extracts of the corpus cardiacum (CC) and fifth ventral ganglion (VG5) stimulated ileal I[formula omitted] in a dose-dependent manner and both caused an increase in K⁺ and Na⁺ absorption as previously observed with cAMP. CC and VG5 had no effect on ileal NH₄⁺ secretion but both inhibited ileal H⁺ secretion. Most of the stimulatory effects of CC and VG were largely abolished by treatment with trypsin and chymotrypsin, suggesting that the stimulants were peptides. CC and VG5 factors were apparently separate compounds because they differed in the time courses of ileal I[formula omitted] response, thermal stability, and extraction properties. Reversed-phase high performance liquid chromatography (RP-HPLC) of water extracts of CC identified two distinct factors (fractions D and F) which stimulated ileal I[formula omitted] and a third factor (fraction G) which had little effect on I[formula omitted], but which caused a five-fold increase in ileal fluid transport (J[formula omitted]). None of these fractions increased rectal J[formula omitted]; moreover, fraction D stimulated rectal I[formula omitted] at higher doses. These results provided the first indication that separa…
aggregated CHO: https://circle.library.ubc.ca/rest/handle/2429/30818
note: PURIFICATION OF A NEUROPEPTIDE FROM THE CORPUS CARDIACUM OF THE DESERT LOCUST WHICH INFLUENCES ILEAL TRANSPORT by NEIL AUDSLEY B.Sc.(HONS), The University of Newcastle Upon Tyne, 1985 A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY in THE FACULTY OF GRADUATE STUDIES DEPARTMENT OF ZOOLOGY We accept this thesis as conforming to the required standard THE UNIVERSITY OF BRITISH COLUMBIA NOVEMBER, 1990 © Neil Audsley, 1990 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 or her representatives. It is understood that copying or publication of this thesis for financial gain shall not be allowed without my written permission. Department The University of British Columbia Vancouver, Canada Date DE-6 (2/88) i Abstract Previous studies on the regulation of salt and water reabsorption in the insect excretory system have concentrated on the rectum, while regulation of the ileum has received little attention. CI" transport is the predominant ion transport process in both the ileum and rectum of the desert locust and drives fluid absorption. The central nervous system (CNS) was surveyed for factors which stimulate Cl'-dependent short-circuit current (Isc) using in vitro flat sheet preparations of locust ileum as a bioassay. All ganglia extracts tested (except the corpora allata) caused significant increases in ileal L^ .. Extracts of muscle tissue, used as a control, had no effect on ileal L. indicating that stimulants were not general metabolites present in locust tissue. Crude extracts of the corpus cardiacum (CC) and fifth ventral ganglion (VG5) stimulated ileal la. in a dose-dependent manner and both caused an increase in K…
has type: Thesis/Dissertation
is shown at: 10.14288/1.0100405
language: eng
degree discipline: Zoology
provider: Vancouver : University of British Columbia Library
publisher: University of British Columbia
rights: For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use.
scholar level: Graduate
type: Text
identifier URI: http://hdl.handle.net/2429/30818