溶血磷脂胆硷对缺血性心室肌电生理的影响

INFLUENCES OF LYSOPHOSPHATIDYLCHOLINE ON EIECTROPHYSIOLOGY OFISOLATED VENTRICULAR MYOCARDIUMUM IN SHEEP

用台氏液加溶血磷脂胆硷（ＬＰＣ）３ｘｌ０－４灌流离体绵羊心室小梁肌，其０期去极化最大速率（Ｖｍａｘ）、静息电位（ＲＰ）、动作电位幅值（ＡＰＡ）、动作电位复极达ＡＰＡ５０％和９０％的时程ＡＰＤ５０、ＡＰＤ９０分别下降３９．８％、１０．４％、１４．５％、２１．３％和１４．８％；用“模拟缺血溶液”加ＬＰＣ３×ＩＯ－４灌流，其Ｖｍａｘ、ＲＰ、ＡＰＡ、ＡＰＤｓ０和ＡＰＤ９０分别下降７８％、２２．７％、２６％、３５．４％和２１％；实验中对“模拟缺血溶液”中各种成分对ＬＰＣ效应的影响进行分析，发现主要的因素是酸中毒。结果表明：ＬＰＣ是心肌缺血中心律失常的重要因素之一，缺血诱导的酸中毒更加重了ＬＰＣ对心肌细胞的毒性作用。

he sheep ventricular myocardial trabeculae were immersed in Tyrode's solution withlysophasphatidylcholine(LPC)3×l0-4。The maximal depolarized rate at phase O(Vmax ),theresting potertial(RP) ,the action potential amplitude(APA),and the action potential durationat 50%and 90%of APA(APD50, APD90)were respestively reduced to 39.8%, 10.4%, 14.5%,2l.3%and l.8%。When the sheep ventricular myocardial trabeculae were immersed in the sim-ulated ischemic solution with LPC 3 X l-4 the Vmax,RP。 APA,APD50 and APD90。were respec-tivelv reduced to 78%,22.7%,26%,35.4%and 2l%。When the influence of every componentin the simulated ischemic solution on the effects of LPC was analysed, the main factor was foundacidosis。These results indicated: LPC was one of the important factors of early cardiac arrhyth-mia caused by myocardial ischemia and the acidosis induced by ischemia increased the toxic effectsof LPC on the myocardial cells。