CO-SECRETION OF AMYLIN AND INSULIN FROM CULTURED ISLET BETA-CELLS - MODULATION BY NUTRIENT SECRETAGOGUES, ISLET HORMONES AND HYPOGLYCEMIC AGENTS

Amylin is a pancreatic islet β-cell peptide hormone which modulates carbohydrate metabolism in skeletal muscle and liver, and could contribute to impaired insulin sensitivity in Type II diabetes. Here we report the first description of amylin secretion from isolated β-cells. We measured amylin secretion from HIT T15 β-cells exposed to glucose, arginine, glucagon, somatostatin, tolbutamide, glyburide, or metformin. With the exception of glucagon at concentrations above 1μM, all compounds induced parallel, dose-dependent changes in secretion of amylin and insulin. We conclude that: 1) insulin and amylin are co-secreted from islet β-cells; (2) nutrient secretagogues and peptide modulators exert direct effects on β-cells to alter amylin and insulin secretion; (3) most modulators of islet β-cell secretion alter amylin and insulin in parallel, but differential secretion can occur; and (4) the HIT cell line is a useful model in which to study amylin metabolism. © 1991.