溶血磷脂胆碱在缺血性心律失常中的作用

Effects of lysophosphatidylcholine in ischemic arrhythmia

用台氏液加溶血磷脂胆碱（ＬＰＣ）３×１０－４ｍｏｌ／Ｌ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ＡＰＡ９０％的时程（ＡＰＤ５０，ＡＰＤ９０）分别下降３９．８％，１０．４％，１４．５％，２１．３％和１４．８％（ｎ＝１２，Ｐ＜０．０１）；用“模拟缺血溶液”和ＬＰＣ３×１０－４ｍｏｌ／Ｌ灌流，其Ｖｍａｘ，ＲＰ，ＡＰＡ，ＡＰＤ５０，ＡＰＤ９０分别下降７８．０％，２２．７％，２６．０％，３５．４％和２１．０％。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，发现其主要因素是酸中毒。结果表明：ＬＰＣ是心肌缺血中心律失常的重要因素之一。

The sheep ventricular myocardial trabeculae were immersed in Tyrode′s solution with lysophosphatidylcholine(LPC)3×10-4mol/L. The maximal depolarized rate at O phase(Vmax), the resting potential (RP), the action potential ampiltude(APA), and the action potential duration at 50% and 90% of APA (APD50, APD90)were reduced 39.8%, 10.4%, 14.5%, 21.3% and 14.8%, respectively(n=12, P<0.01). When the sheep ventricular myocardial trabeculae were immersed in the simulated ischemic solution with LPC 3×10-4mol/L, the Vmax, RP, APA, APD50, and APD90 were reduced 78.0%, 22.7%, 26.0%, 35.4% and 21.0%, respectively. When the influence of every component in the simulated ischemic solution on the effects of LPC was analysed, the main factor was found to be acidosis. These results indicated that LPC was one of the important factors of early cardiac arrhythmia caused by myocardial ischemia and the acidosis induced by ischemia increased the toxic effects of LPC on the myocardial cells.