Hyperinsulinemia in rats with obesity-inducing amygdaloid
lesions.
King, Bruce M., Jack T. Cook, and Mary F. Dallman.
Department of Psychology, University of New Orleans, New Orleans,
Louisiana 70148; and Department of Physiology, University of
California, San Francisco, California 94143
APStracts 3:0186R, 1996.
Electrolytic lesions of the posterodorsal aspects of the medial
division of the amygdala in female rats results in hyperphagia and
excessive weight gain. In the present study, the effects of such
lesions on plasma insulin, glucose, corticosterone, and ACTH were
assessed during a period of food restriction and again after a 15-day
period of food ad libitum. Compared to control animals, the rats with
amygdaloid lesions were hyperinsulinemic under both conditions, and
gained substantially more weight when fed ad libitum. No difference
between groups was observed for the other hormones. It is concluded
that damage to the posterodorsal aspects of the medial amygdala
results in a primary metabolic dysfunction that accounts, at least in
part, for the overeating and excessive weight gain.
Received 25 September 1995; accepted in final form 2 May 1996.
APS Manuscript Number R600-5.
Article publication pending Am. J. Physiol. (Regulatory Integrative
Comp. Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 28 May 96