氯化汞对培养乳鼠心肌细胞和家兔窦房结电活动的影响

氯化汞对培养乳鼠心肌细胞和家兔窦房结电活动的影响１马欣荆伟庆赵松珍２（西安医科大学药理学教研室，２第一附属医院神经科，西安７１００６１）汞是一种微量元素，长期大剂量接触可产生心脏毒性作用，如引起不同类型的心律失常［１］．但是，汞对心血管系统的毒性机理...

Effects of mercuric chloride on electric activity of cultured neonatal rat myocardial cells and rabbit sinoatrial node

Glass microelectrode technique was used to investigate the effects of mercuric chloride (HgCl₂) on the electrophysiological action of cultured neonatal rat myocardial cells and rabbit sinoatrial node. HgCl₂5 μmol·L^-1 decreased the amplitude and the V_max of action potential (P<0.05), shortened the duration of action potentials at 50% and 100% of repolarization of primary cultured rat myocardial cells. HgCl₂ 20 μmol·L^-1 decreased rabbit sinus rate and V_max of phase 0 of action potentials of sinoatrial node was decreased from 3.2±0.9 V·s^-1 to 1.9±0.6 V·s^-1, but the sinus cycle length increased. The action potential phase 4 depolarization of the isolated rabbits sinoatrial node slowed from 61±4 mV·s^-1 to 22±4 mV·s^-1. The study suggests that HgCl₂ induced arrythmias may be related to the blockade effect on Ca²⁺ channel of myocardium cells.