牛磺酸对心肌缺血／再灌注损伤的保护作用及机制探讨

PROTECTIVE EFFECTS OF TAURINE ON MYOCARDIUM OF ISCHEMIA/REPERFUSION AND ITS UNDERLYING MECHANISM

离体大鼠心脏灌流模型的实验表明，牛磺酸除明显减轻再灌注心肌的钙超载和脂质过氧化外，还显著改善心肌肌浆网（ＳＲ）的钙转运功能，牛磺酸使肌浆网的钙─三磷酸腺苷酶活性较缺血／再灌注组升高１．１１倍，摄钙初速率和最大摄钙量分别升高６１．７±１．１％和４０．９±６．４％。牛磺酸可直接拮抗氧自由基灌流导致的心肌细胞和ＳＲ的损伤，对离休ＳＲ无直接作用，对心肌局部的肾素─血管紧张素系统也未见有影响。研究结果显示，牛磺酸的心肌保护作用还与其降低再灌注时心肌的脂质过氧化有关。

The protective effect of taurine on myocardium of ischemia/reperfusion(I/R) and its underlying mechanism were observed on isolated rat heart. Taurine inhibited myocardial calcium overload and lipid peroxidation, improved calcium transport function in SR with increase in Ca2+-ATPase activity of SR by 1. 11-fold,initial rate and capacity of calcium uptake by 61. 76±1. 1% and 40. 9 ±6. 4% , respectively. No effects on isolated SR and myocardial renin-angiotensin system were found. Taurine inhibited the effect of oxygen free radical(OFR) on myocardium by protecting the function of SR. The initial rate and capacity of calcium uptake were increased by 63. 1±14. 15 and 36.0±5.2% vs. simple OFR group. The results indicate that the effects of taurine on I/R are related to calcium homeostasis,and the inhibition of myocardial lipid peroxidation after reperfusion is probably one of the mechanisms underlying the protective effect of taurine.