TY - JOUR AU - FANG Da-chao AU - ZONG Xian-gang AU - JIN Man-wen AU - ZHOU Shao-ming AU - JIANG Ming-xing PY - 2016 TI - Antifibrillatory effect of berberine JF - Acta Pharmacologica Sinica; Vol 7, No 4 (July 1986): Acta Pharmacologica Sinica Y2 - 2016 KW - N2 - Berberine (Ber 1 mg/kg iv), a quaternary ammonium alkaloid, distinctly elevated the ventricular fibrillation threshold(159+/-41%) to electrical stimulation in anesthetized cats. It increased the duration of action potential (APD) at 20% and 90% of repolization (APD20, APD90) and effective refractory period (ERP) of isolated guinea pig papillary muscles. These effects appeared 1 min after exposure to Ber and reached a steady state within 20 min. Ber prolonged APD90 and ERP by a maximum of 53+/-25% and 63+/-35%, respectively. EC50 was 22 microM. These effects were abolished after Ber was washed out with Tyrode’s solution in 30 min. Associated with the prolongation of APD and ERP, the isometric contractile force of the preparation was increased, but no changes in resting potential, amplitude and maximal upstake velocity of the action potential were seen in the presence of Ber. UR - http://www.chinaphar.com/article/view/5027