Serum FSH, LH and the ovarian response to exogenous gonadotropins in alloxan diabetic immature female rats.

Abstract

Alloxan diabetes was induced in immature female rats at 22 days of age. When autopsied between 29 and 38 days of age, these rats had reduced body, ovarian and uterine wt as compared to the controls; these defects were corrected by insulin treatment. Matching feeding of the controls to that of diabetics caused a similar, but lesser, reduction in body and organ wt. Ovaries of hypophysectomized diabetics regressed more than those of hypophysectomized controls. Following FSH treatment of the insulin-treated diabetics and hypophysectomized diabetics, the percentage ovarian weight increases, above those of saline-injected controls, were slightly but not significantly higher than that of the hypophysectomized diabetics; their absolute wt were significantly higher, however. When exposed to various doses of FSH, augmented by hCG, ovarian wt of diabetic females were always significantly below those of controls. Insulin treatment of the diabetics resulted in essentially normal dose-response curves. Serum FSH, but not LH, concentrations, as determined by double antibody radioimmunoassays, were higher in alloxan diabetes and foodrestricted intact rats than in ad lib-fed controls. The results indicate that ovarian failure in immature diabetic female rats is probably not due to a lack of gonadotropins from the pituitary, but to factors involved in ovarian responses to gonadotropins. (Endocrinology91: 1172, 1972)