AJP - Regulatory, Integrative and Comparative Physiology, Vol 261, Issue 6 1554-R1559, Copyright © 1991 by American Physiological Society
Dietary fat, hypothalamic glutamate decarboxylase, and food intake of streptozotocin-diabetic rats
J. L. Beverly, M. H. Oster, T. W. Castonguay and J. S. Stern
Food Intake Laboratory, University of California, Davis 95616.
The association among changes in glucose status, glutamate decarboxylase
(GAD) activity, and food intake was evaluated in several hypothalamic areas
of streptozotocin-diabetic rats fed a low- (12% of calories as fat) or
high-fat diet (59% of calories as fat). Control rats consumed approximately
90 kcal/24 h of either diet, whereas diabetic rats consumed approximately
150 kcal/24 h of the low-fat diet and approximately 100 kcal/24 h of the
high-fat diet. At the end of the study, diabetic rats fed the high-fat diet
weighed more and had higher retroperitoneal fat depot weights (P less than
0.05) than diabetic rats fed the low-fat diet. In diabetic rats, GAD
activity was 15-20% higher in the ventromedial nucleus (P less than 0.01)
but similar to controls in the lateral hypothalamus, paraventricular
nucleus, and area postrema. Diet did not affect GAD activity in the brain
areas studied. The increase in ventromedial nucleus GAD activity was not
associated with the level of food intake and was the likely result of
altered glucose homeostasis in diabetic rats.
