SHORT-TERM EFFECTS OF OESTRADIOL BENZOATE IN NORMAL, HYPOPHYSECTOMIZED AND ALLOXAN-DIABETIC MALE RATS

Abstract

SUMMARY Studies were undertaken to determine the effects and possible mode of action of 17β-oestradiol benzoate (OEB) in alloxan-diabetic male rats. Adlibitum or pair-fed normal, diabetic, and hypophysectomized rats received daily subcutaneous injections of 10 μg OEB for 10 days. In normal rats, OEB decreased plasma glucose, increased plasma immunoreactive insulin, growth hormone and corticosteroid levels, increased pancreatic β-cell granulation, and enhanced glucose stimulation of insulin release in vitro. In alloxan-diabetic rats, OEB treatment decreased urinary glucose excretion, increased plasma growth hormone and corticosteroid levels and slightly enlarged the pancreatic islets of Langerhans. In hypophysectomized rats, OEB decreased plasma glucose, increased plasma insulin levels, and slightly enlarged the pancreatic islets of Langerhans. These results suggest that OEB affects experimental diabetes by a direct action on the pancreas, promoting insulin formation, and possibly by an indirect action mediated through hypophysial secretions.