药物预处理对离体大鼠缺血再灌注损伤心肌的保护作用

Pretective Effects of Pharmacological Preconditioning on Myocardial Ischemia──Reperfusion Injury in Isolated Rat Rearts

为观察药物预处理对缺血再灌注所致心肌损伤是否有保护作用，离体大鼠心脏在30min全心缺血和30min再灌注前用10（-7）M／L去甲肾上腺素和1mg／L苯肾上腺素灌注5min，随后用正常K—H液冲洗10min。结果发现，去甲肾上腺素和苯肾上腺素预处理可以1）显著降低再灌注性心律失常发生率；2）增加再灌注期间的心率和冠脉回流量；3）减少心肌细胞内CK和LDH的漏出以及抑制心肌MDA含量的升高。结果表明，去甲肾上腺素和苯肾上腺素预处理对缺血——再灌注损伤心肌有保护作用。其机制可能和它们与α—肾上腺素能受体结合，激活PKC环节有关。

the aim of this study was to determine whether pharmacologic preconditioning, without a short episode of myocardial hypoxia or ischemia,had the protective effect on the myocardial injury induced by ischemia-reperfusion. Isolated rat hearts were perfused with lmg/Liter of phenylephrine or 10(-7)M/liter of norepinephrine for 5 min followed by a 10-min washout period (preconditioning) before the induction of 30min of global ischemia and 30min ofreperfusion. The results showed that phenylephrine and norepinephrlne preconditioning could:1)reduce the incidence of reperfusion-induced arrhythmia; 2) increase the heart rate and the coronary flow during reperfusion; 3)decrease the leakage of CK. LDH from myocardial cell andthe contend of MDA. the results indicated that phenylephrine and norepinephrine preconditioning could protect the rat myocardium from ischemia-reperfusion injury, which was associated with activation of PKC after phenylephrine or norepinephrine connected with α1-adrenoceptor.