Insulin release from the perfused rat pancreas. Mode of action of tolbutamide

Dextran-linked tolbutamide causes first-phase insulin release when perfused through the isolated rat pancreas. The linked sulphonylurea is also able to stimulate the membranal adenylate cyclase present in mouse islets. These facts make it highly likely that sulphonylureas exert their pharmacological action by interaction with the plasma membrane. Their action may be mediated via the adenylate cyclase enzyme.