Effects of short-term dehydroepiandrosterone treatment on serum and pancreatic insulin in Zucker rats

Lean and obese female Zucker rats were treated with 0.6% dehydroepiandrosterone (DHEA) from 5 until 10 wk of age and comparisons made to both ad libitum-fed and weight-matched groups. Within genotype, body weights and cumulative food intakes of DHEA and weight-matched groups were not different. Fat pad weights of DHEA rats were significantly lower than those of nontreated groups. Pancreatic insulin content, whether expressed per pancreas or per gram pancreas, was not lowered by DHEA treatment. Fasting serum insulin levels were not altered in lean rats but were significantly lower in DHEA obese rats than in either nontreated obese group. Glucose metabolism (conversion to CO₂, fatty acids or glyceride-glycerol) in isolated adipocytes was similar in all groups except that obese rats had greater glyceride-glycerol production than lean rats. Glucose conversion to CO₂ in soleus muscle was lower in obese rats than in lean rats. Basal and insulin-stimulated glycogen production was lower in DHEA and weight-matched obese rats than in any other group. Ad libitum-fed lean rats had higher insulin-stimulated glycogen production than DHEA lean and all groups of obese rats. Short-term DHEA treatment of obese Zucker rats lowers serum insulin levels without improvement of insulin resistance in peripheral tissues and without lowering pancreatic insulin content.