Insulin Secretion During Development: Response of Isolated Pancreatic Islets of Fetal, Newborn and Adult Rats to Theophylline and Arginine

Abstract

Pancreatic islets of 21-day-old fetal, five-day-old newborn and adult female rats were isolated by the collagenase method and incubated in vitro for 90 minutes. The insulin released into the medium was measured in response to theophylline and arginine both at concentrations of 1 and 10 mM. Only the 10 mM concentration of theophylline without the addition of glucose enhanced the insulin release significantly in all three age groups. In the presence of glucose both theophylline concentrations stimulated insulin secretion; however, there was no dose response curve. Whereas 1 mM of 1-arginine with and without the addition of glucose had no effect, 10 mM produced a significant insulin release only in the presence of glucose in all three age groups tested. 1 Supported by United States Public Health Service Grants Nos. HD 02171 and AMO 5077.