Document Detail


Intracerebroventricular infusion of leptin elevates the secretion of luteinising hormone without affecting food intake in long-term food-restricted sheep, but increases growth hormone irrespective of bodyweight.
MedLine Citation:
PMID:  11139771     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Leptin can act as a satiety factor and exert neuroendocrine effects, but most studies have been performed in fasted animals. We aimed to determine the effect of chronic under-nutrition on the response to a 3-day intracerebroventricular infusion of leptin with regard to food intake and the secretion of pituitary hormones. Ovariectomised ewes (n=6) had a mean (+/-s.e.m. ) bodyweight of 56+/-0.8 kg on a diet available ad libitum (ad lib) or 33.4+/-1 kg on a restricted diet. The differential bodyweight was achieved by dietary means over a period of 6 months prior to the commencement of the study. Leptin (4 microg/h) or vehicle (artificial cerebrospinal fluid (aCSF)) was infused into the third cerebral ventricle for 3 days. Blood samples were taken prior to commencement and on day 3 of infusion for the assay of plasma hormone levels. The experiment was repeated one week later in a cross-over design. Food intake and metabolic status were monitored daily. The luteinising hormone (LH) pulse amplitude was lower (P<0.05) but plasma growth hormone (GH) levels were higher (P<0.05) in the food-restricted animals. Plasma levels of glucose, lactate, insulin, urea and triglycerides were similar in the two groups but non-esterified fatty acid levels were higher (P<0.01) in the animals on an ad lib diet. Leptin reduced (P<0.05) food intake only in the animals fed an ad lib diet. Leptin increased (P<0.05) the secretion of LH in the food-restricted group only and increased (P<0.05) GH irrespective of bodyweight. In conclusion, leptin does not alter food intake in animals on a restricted diet but can increase the secretion of LH in the same animals. The treatment of leptin was not sufficient to reduce plasma GH levels in the food-restricted animals, suggesting that other factors or mechanisms must be involved in the regulation of this axis.
Authors:
B A Henry; J W Goding; A J Tilbrook; F R Dunshea; I J Clarke
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  The Journal of endocrinology     Volume:  168     ISSN:  0022-0795     ISO Abbreviation:  J. Endocrinol.     Publication Date:  2001 Jan 
Date Detail:
Created Date:  2001-01-26     Completed Date:  2001-02-22     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  0375363     Medline TA:  J Endocrinol     Country:  England    
Other Details:
Languages:  eng     Pagination:  67-77     Citation Subset:  IM    
Affiliation:
Prince Henry's Institute of Medical Research, PO Box 5152 Clayton, Victoria 3168, Australia.
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MeSH Terms
Descriptor/Qualifier:
Analysis of Variance
Animals
Chronic Disease
Cross-Over Studies
Fatty Acids, Nonesterified / blood
Female
Follicle Stimulating Hormone / blood,  secretion
Growth Hormone / blood,  secretion*
Injections, Intraventricular
Leptin / administration & dosage*,  pharmacology
Luteinizing Hormone / blood,  secretion*
Nutrition Disorders / physiopathology*
Ovariectomy
Satiety Response / drug effects*
Sheep
Chemical
Reg. No./Substance:
0/Fatty Acids, Nonesterified; 0/Leptin; 9002-67-9/Luteinizing Hormone; 9002-68-0/Follicle Stimulating Hormone; 9002-72-6/Growth Hormone

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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