Pancreatic metallothionein: Protection against cadmium-induced inhibition of insulin secretory activity

Abstract

Mouse liver and pancreatic concentrations of metallothionein were determined by gel filtration at several intervals after the ip administration of cadmium acetate. Hepatic concentrations of the protein reached peak values 48 hr after the injection, whereas the pancreatic concentrations were highest at 6 hr. The exposure of mouse isolated pancreatic islets to a concentration of 1 × 10 −6 m cadmium significantly reduced glucose-stimulated insulin secretion. When mice were administered cadmium 6 hr prior to islet isolation, the time required for peak concentrations of metallothionein to develop in the pancreas, subsequent exposure to the metal did not reduce glucose-stimulated insulin secretion. The results suggest that the pancreas synthesizes metallothionein and that the protein serves a protective role against the acute effects of cadmium.