Effect of N-methyl berbamine on calcium-activated potassium currents in rat mesentric resistance vascular smooth muscle cells

AIM: To investigate the ionic mechanism of N-methyl berbamine (NMB) on lowering blood pressure by recording calcium-activated potassium currents (IK·Ca in the rat mesenteric resistance vascular smooth muscle cells. METHODS: Using standard whole cell recording method. RESULTS: At potential of + 60 mV, NMB 0.1, 1 and 10 μmol · L-1 activated IK·Ca from pretreatment (33.6±2.0) pA · pF-1 to (35.7±1.9), (42.9± 2.7) and (59.4±1.4) pA · pF-1 (n = 6 cells from 6 rats, P < 0.01), respectively. CONCLUSION: NMB could increase IK·Ca in the rat mesenteric resistance vascular smooth muscle cells, which may be one of the mechanisms of lowering blood pressure.