ABSTRACT
Aim To investigate the insulinotropic effect of telmisartan anrl the underlying electrophysiological mechanism.Methods Islets and cells were isolated from Wistar rats.Islets were incubated with drugs un¬der different conditions, then supernatant liquid was collected for insulin secretion.Intracellular Ca" + ( Ca'+ j) levels of (3-cells were measured by calcium imaging technology.Patch-clamp technology was ap¬plied to detect effects on voltage-gated potassium chan¬nel ( Kv ) , and voltage-gated calcium channel ( VGCC ).Results Not affecting insulin secretion un¬der low glucose condition, telmisartan dose-dependent- ly stimulated insulin secretion under high glucose con¬ dition, and stimulation was enhanced with increasing glucose concentration.Acute increases of Ca' + concentration were elicited by telmisartan under high glucose condition.Telmisartan decreased current den¬sity of Kv channel, and increased VGCC current densi¬ty.Conclusions Telmisartan enhanced Ca~+ ; lev¬els of p-cells through its action on Kv channel and VGCC, thereby amplifying glucose-stimulated insulin secretion.