AJP - Endocrinology and Metabolism, Vol 262, Issue 6 E963-E967, Copyright © 1992 by American Physiological Society
Correlation between plasma beta-cell tropin concentrations and body weight in obese rhesus monkeys
J. L. Morton, M. Davenport, A. Beloff-Chain, N. L. Bodkin and B. C. Hansen
Clore Laboratory for the Biological Sciences, University of Buckingham, United Kingdom.
The fasting plasma concentration of the pituitary peptide beta-cell tropin
[beta-CT, adrenocorticotropic hormone-(22-39)] was measured in 17 rhesus
monkeys from a colony known to develop spontaneous obesity. The weight of
the animals was 9.4-23.9 kg (12-46% body fat). Plasma beta-CT
concentrations were 0.03-0.84 nmol/l and were strongly correlated with body
weight (P = 0.014, r = 0.584). Plasma beta-CT was also correlated with
plasma insulin concentration as a power function (P = 0.011, r = 0.600) and
with percent body fat up to 40% (P = 0.003, r = 0.0804). Plasma insulin is
also correlated with body weight (P = 0.015, r = 0.578) but does not
decline when body fat is in excess of 40%, supporting the hypothesis that
beta-CT may be involved in a feed-back control mechanism, perhaps mediated
by insulin. Because beta-CT has been shown in rodent studies to be a potent
insulin secretagogue and lipogenic agent, it is possible that beta-CT is
causally involved in the development of obesity and that there may be
central determinants of obesity mediated through pituitary secretion of
beta-CT.
