炙甘草汤干预缺氧对离体豚鼠心肌细胞跨膜电位的影响

目的:本实验通过观察炙甘草汤对缺血缺氧心肌电生理活动的影响,探讨其对心肌的保护和抗心律失常作用的机制。方法:玻璃微电极细胞内记录的方法,观察正常灌流液、缺血缺氧灌流液和缺血缺氧+炙甘草汤(20mg/ml、40mg/ml and 80mg/ml)灌流液对豚鼠左心室流出道慢反应自律细胞及心室乳头肌细胞动作电位的影响。结果:(1)缺血缺氧时左室流出道细胞APD50、APD90和APD均明显缩短(P<0.05),VDD及RPF显著变慢(P<0.01);而加入不同剂量炙甘草汤(20mg/ml、40mg/ml and80mg/ml)可剂量依赖性的拮抗由缺血缺氧介导的APD50、APD90和APD的缩短(P<0.05,0.01或0.001),使VDD及RPF加快基本恢复正常的节律。此种干预作用以80mg/ml炙甘草汤最为明显。(2)缺血缺氧时心室肌细胞的Vmax、APD50和APD90及APD均明显减小(P<0.05);在缺血缺氧灌流液中加入不同剂量的炙甘草汤后上述效应得到明显改善。结论:提示炙甘草汤对缺血缺氧导致的左心室流出道慢反应自律细胞的异常电生理所诱发的心律失常及心肌细胞损伤有显著保护作用。

Effects of Zhigancao Decoction on isolated guinea pig cardiac cells transmembrane potential induced by hypoxia

Objective: To observe the interferential effects of Zhigancao Decoction on electrophysiological activity of left ventricular outflow tract and papillary muscles induced by ischemia-hypoxia and its cardiac protection and anti-arrhythmic effects of the mechanism.Methods: By using conventional intracellular microelectrode technique to record transmembrane potential parameters of action potential duration(APD),50% of APD(APD50),90% of APD(APD90),velocity of diastolic depolarization(VDD) and rate of pacemaker firing(RPF) and maximal rate of depolarization(Vmax),the maximal diastolic potential(MDP) in left ventricular outflow tract and papillary muscles cells of normal contral group,ischemia-hypoxia group and ischemia-hypoxia adding Zhigancao Decoction group.Result:(1) Compared with normal contrals,action potential of APD50,APD90,APD of left ventricular outflow tract in ischemia-hypoxia group were significantly shortened(P <0.05),VDD and RPF significantly slowered(P < 0.01);The addition of 20mg / ml、40mg / ml and 80mg / ml Zhigancao Decoction respectively resulted in a significant inhibition induced by ischemia-hypoxia in APD50,APD90,APD(P < 0.05,0.01 或 0.001) and VDD and RPF(P < 0.05).The spontaneous discharge frequency recovered to the normal rhythm.The inhibitions relyed on the doses of Zhigancao Decoction and the most markable inhibition occurred at 80mg / ml Zhigancao Decoction.(2) Aaction potential of APD50,APD90,APD of ventricular papillary muscles in ischemia-hypoxia group were significantly shortened(P < 0.05),Vmax significantly slowered(P < 0.05);The addition varies doses of Zhigancao Decoction could inhibit the effects induced by ischemia-hypoxia varies from doses.Conclusion: Zhigancao Decoction could counteract arrhythmia related to ventricular outflow tract and provide protection to myocardial injury induced by ischemia-hypoxia.