反向钠钙交换体参与低钾加重的缺血再灌注后的心功能损伤

目的观察低钾灌注液（含3.1 mmol/L K＋的KH液）对缺血再灌注后对心功能的影响,并评价反向钠钙交换体在此效应中的作用。方法离体灌流大鼠心脏接受1 h缺血/1 h再灌注处理,通过记录左心室发展压（LVDP）、左心室舒张末压（LVEDP）的变化,评价不同处理对心脏功能的影响。结果正常钾KH液（含5.9 mmol/L K＋的KH液）灌注心脏在接受缺血再灌注处理后,LVDP恢复至缺血前（58.1±8.3）%,LVEDP升高至（23.2±1.7）mm Hg。与正常钾KH液灌注条件相比,低钾KH液灌注使得缺血再灌注处理后LVDP进一步降低（P〈0.01）,LVEDP进一步升高（P〈0.01）。10μmol/L KB-R7943（反向钠钙交换体抑制剂）改善低钾灌注液的作用显著大于正常钾KH液。结论低钾KH液灌注加重缺血再灌注后的心功能损伤,其作用与激活反向钠钙交换体活性有关。

Sodium/calcium exchanger mediates the aggravated effects of low potassium perfusion on ischemia reperfusion-induced heart injury

OBJECTIVE To observe the effects of perfusion with KH buffer containing low potassium(3.1 mmol/L) on ischemia reperfusion-induced heart injury,and investigate the underlying mechanism.METHODS The isolated rat hearts were subjected to 1 h ischemia/1 h reperfusion.The changes of left ventricular developed pressure(LVDP) and left ventricular end-diastolic pressure(LVEDP) were recorded and analyzed.RESULTS In heart perfused with KH buffer containing potassium at the concentration of 5.9 mmol/L(standard),the LVD...