Effects of Aminoguanidine on Glucagon and Insulin Release from Rat Pancreatic Islet

Abstract

Aminoguanidine (AG) is a potential therapeutic agent for preventing the generation of advanced glycation end products in diabetes mellitus. In this study, the effects of AG on glucagon and insulin secretion in in vitro rat pancreatic islets were investigated. The islets were aseptically isolated and cultured in tissue culture medium 199 for 48h with or without 9.1mM AG (1mg/ml). After the culture, 50 islets were perifused in Krebs-Ringer bicarbonate buffer containing 20mM arginine or 1U/ ml pancreozymin in the presence of 3.3mM glucose. Islets previously exposed to AG showed similar glucagon response to control islets at a 20mM arginine concentration, and insulin response, too. Glucagon release caused by 1U/ml pancreozymin from the islets previously exposed to AG was also not different from that of the control islets, but the release of insulin was much lower than that of control. These results suggest that AG would not be toxic to a-cells but toxic to β-cells at high concentrations, although there is slightly different sensitivity to β-cell secretagogues.