[Effects of berberine on single Ca2+ channel current in cultured embryonic chick ventricular myocytes]

On cultured embryonic chick ventricular myocytes, we investigated the influence of berberine (BR) on single Ca2+ channel current using patch clamp technique with cell-attached configuration. The results showed that BR could increase the single Ca2+ channel current significantly and the increases of open availability (Ps) and open probability (Po) caused by BR were 114.2% (P < 0.001) and 75.3% (P < 0.05), respectively. The beta-receptor antagonist propranolol and Ca2+ channel blocker ispotin could reverse the effects of BR on single Ca2+ channel, suggesting that (1) BR works as a Ca2+ channel agonist; (2) the regulating effects of BR on single Ca2+ channel is depending upon the phosphorylation process induced by beta-receptor activity.