Insulin Secretion and Content in Isolated Rat Pancreatic Islets Following Treatment with Gestational Hormones

Insulin secretion after glucose stimulation and residual insulin content was studied in islets of Langerhans isolated from adult female rats which had been treated for 1–2 weeks with progesterone (P),estriol (E3), 17β-estradiol (E2), human chorionic somatomammotropin (HCS), E3 + P, E2 + P, HCS + P, or E3 + HCS + P. An increase in insulin secretion was observed after P treatment which was not further augmented by E3 + P and was reversed by E2 + P treatment. E2 treatment alone led to a smaller than normal insulin secretion response to glucose stimulation. Blunting of P-enhanced glucose-stimulated insulin secretion was also observed after E3 + HCS + P, but not after HCS + P. Residual islet insulin content increased after P and E3 + P, but not after E2 + P administration. These results indicate that these gestational hormones do not produce additive effects on glucosestimulated insulin secretion or on total islet insulin content. (Endocrinology91: 977, 1972)