激活细胞膜Na＋／H＋交换对心肌缺血再灌注损伤的影响

EFFECT OF ACTIVATION OF Na +/H + EXCHANGE SYSTEM ON ISCHEMIA REPERFUSION INJURY

在离体大鼠等容收缩心脏灌流模型上，观察激活细胞膜Ｎａ＋／Ｈ＋交换对心肌缺血后再灌注性损伤的影响。采用经典ＮＨ４Ｃｌ负荷方法以激活细胞膜Ｎａ＋／Ｈ＋交换，结果表明，激活Ｎａ＋／Ｈ＋交换加重缺血后再灌注心脏血液动力学障碍，增加冠脉流出液中乳酸脱氢酶的活性，并使心肌组织中Ｎａ＋、Ｃａ２＋超负荷及Ｋ＋丢失加重。提示细胞膜Ｎａ＋／Ｈ＋交换是心肌缺血后再灌注损伤的发病机理之一。

The effect of activation of Na +/H +exchange on ischemic myocardium was observed in the model of ischemic reperfusion injury in the isolated rat hearts. The perfused isovolumic contracting rat hearts were subjected to 20 mmol/L NH 4Cl loading for promoting the Na +/H +exchange. The results indicated that activation of Na +/H +exchange inhibited the recovery of ventricular function significantly, and exacerbated the myocardial injury as evidenced by increase in release of LDH, associated with the accumulation of intracellular Na +, Ca 2+ and the loss of intracellular K +. It is suggested that the Na +/H +exchange system may play an important role in the post ischemic reperfusion injury.