AJP - Regulatory, Integrative and Comparative Physiology, Vol 255, Issue 5 787-R793, Copyright © 1988 by American Physiological Society
Food restriction normalizes somatic growth and diabetes in adrenalectomized ob/ob mice
P. U. Dubuc and H. J. Carlisle
Sansum Medical Research Foundation, Santa Barbara 93105.
Carcass composition was determined in intact and adrenalectomized (ADX)
ob/ob mice after 6 wk of food restriction from weaning (21 days). Diets
(2.6 or 3.2 g/day) led to reduced weight gain in intact ob/ob mice, but fat
deposition was still greater, and lean growth was less than isocalorically
fed lean mice. When diet was combined with ADX, obese mice fed 3.2 g/day
had rates of fat-free body growth equal to ad libitum-fed lean mice but
still gained more weight and deposited more fat. With 2.6 g/day, however,
body weight gain, fat deposition, fat-free body growth, and protein
deposition were all similar to intact lean mice receiving the same diet.
Neither diet nor diet combined with ADX improved the defective
thermoregulation of obese mice tested at 23 degrees C, 8 degrees C, or in
response to food deprivation or food ingestion. Together, diet and
adrenalectomy reduced blood glucose and insulin levels in ob/ob mice, and
with the 2.6 g/day diet, the values of each were the same as littermate
lean controls. The present results indicate that adrenal glucocorticoids
are necessary for maintaining elevated fat deposition at the expense of
lean body growth in dieted ob/ob mice, whereas hyperphagia, defective
thermoregulation, energy efficiency, and diabetes are still expressed after
surgery.
