Tetrandrine inhibits inward rectifying potassium current in cultured bovine aortic endothelial cells

AIM: To study the effect of tetrandrine (Tet) on inward rectifying potassiu m current in cultured bovine aortic endothelial cells. METHODS: Inward rect ifying potassium current (IRK) was observed by the whole cell patch-clamp t echnique. RESULTS: IRK was inhibited by Tet in a concentration-dependent ma nner and recovered to normal after wash with drug-free external solution. I RK was reduced from (582 +/- 48) pA to (221 +/- 40) pA at a holding potenti al of - 70 mV by Tet 30 mu mol/L. IC50 was 2.8 mu mol/L. CONCLUSION: Tet in hibited inward rectifying potassium current in cultured bovine aortic endot helial cells.