Morphological changes in pancreatic B-cells after intravenous administration of forskolin

The morphological changes in rat pancreatic islets were studied after intravenous injection of forskolin (1.5 mg/kg), an activator of adenylate cyclase, to male Wistar rats. A high amount of insulin containing granules was observed on PAP immunostained paraffin sections. Ultrastructural study of islet B-cells demonstrated enlarged perinuclear space, dilated cisternae of rough endoplasmic reticulum and activated Golgi complex with numerous vesicles. The results suggest that intravenous administration of forskolin produces a modest increase of B-cell synthetic activity in the pancreatic islets of rats. It is assumed that forskolin affects pancreatic B-cells via increased cAMP.