GENDER DIFFERENCES IN ADRENAL-CORTEX STEROID-PRODUCTION IN SHR N-CORPULENT RATS/

Gender differences in adrenal steroid hormone production and serum ste roid hormone levels were compared in the spontaneous hypertensive/NIH- corpulent (cp) rat, which exhibits characteristics of both obesity and non-insulin-dependent diabetes mellitus. The study demonstrated that adrenal gland size correlated with adrenal production and serum levels of steroid hormones. Obese female SHR/N-cp rats were more steroidogen ic than male SHR/N-cp rats; the size of their adrenal glands was twice that of the males (70 vs 33 mg). Body weights averaged 666 g for fema les and 829 g for males. Obese female rats had significantly higher se rum concentrations of both corticosterone (827 vs 536 ng/ml) and aldos terone (675 vs 482 pg/ml) than obese male rats. As determined by in vi tro assay, adrenal cortex production of corticosterone (2157 vs 1435 n g/30 min) and aldosterone (13.3 vs 9.5 ng/30 min) was significantly hi gher in obese female than in obese male rats. Adrenal production of te stosterone in the in vitro assay was also significantly higher for obe se female than male rats; however, adrenal estrogen production in obes e rats did not differ significantly. The type of carbohydrate consumed (sucrose > starch) significantly affected serum levels of corticoster one, but not aldosterone, testosterone, or estrogen. Gender difference s in adrenal steroid production and serum steroid levels suggest that hyperglycemia in obese SHR/N-cp rats may be, in part, the result of ex cess adrenal production of steroid hormones.