卡托普利心脏停搏液对缺血再灌注心肌NOS活性和NO产生的影响

目的：探讨卡托普利心脏停搏液对缺血再灌注心肌保护作用的机制。方法：１２只绵羊，随机均分为对照组（Ｉ组）和卡托普利组（Ｉ组）。常规建立体外循环，心脏停搏６０分钟，再灌注３０分钟。Ｉ组采用仁济医院冷晶体停搏液，ＩＩ组在停搏液中加入卡托普利２３μｍｏｌ／Ｌ。观察冠状窦血中一氧化氮（ＮＯ）、肌酸磷酸激酶（ＣＰＫ）、环磷酸鸟苷（ｃＧＭＰ）、心肌丙二醛（ＭＤＡ）含量及心肌ＮＯ合酶（ＮＯＳ）同功酶活性的变化，监测心肌功能。结果：再灌注后Ｉ组心肌血ＮＯ、ＣＰＫ、ｃＧＭＰ、心肌ＭＤＡ均明显升高，Ｉ组低于Ｉ组（Ｐ＜０．０５或０．０１）。ＩＩ组再灌注后心肌原生型ＮＯ合酶（ｃＮＯＳ）活性明显高于Ｉ组，而诱导型ＮＯ合酶（ｉＮＯＳ）及总ＮＯＳ活性显著低于Ｉ组（Ｐ＜０．０１或０．００１）。两组再灌注后心肌功能均降低，Ｉ组较Ｉ组更为显著。再灌注后ＮＯ的变化与心肌ＭＤＡ和ＣＰＫ之间呈正相关（Ｐ＜０．００１和０．０１）。结论：缺血再灌注心肌损伤与过量ＮＯ产生有关，卡托普利通过调节ＮＯＳ同功酶活性，维持正常ＮＯ水平起到保护作用。

The Protective Effect of Captopril-enriched Cardioplegic Solution on Myocardial NOS Activity and NO Prodution after InchemicReperfusion

Aim:This study was conducted to evaluate the protective effects of captoprilenriched cardioplegic solution on myocardial nitric oxide synthesis (NOS) and nitric oxide(NO) production after ischemic reperfusion.Method:The study consisted two groups of sheep.Group I(n=6) received cold crystalloid cardioplegia.Group II(n=6) received cardioplegia as same as group I but added captopril 23 mol/L.Blood samples were taken from coronary sinue at three different time intervals for assess following parameters:NO,CPK,cGMP.Myocardial specimens were also taken for MDA,iNOS,cNOS and NOS activities.Assessment of heart function including MAP,LVSP,LVEDP and dp/dtmax were performed at the same time intervals.Results:Plasma levels of NO,CPK,cGMP and myocardial MDA were increased significantly in group I after reperfusion 5 minutes and 30 minutes as compared with group II.cNOS activity was increased and iNOS and NOS activities were decreased significantly in group II.The heart function was compromised in both groups.There was a positive correlation between the change of NO and myocardial MDA and CPK.Conclusion:The excessive production of NO during reperfusion may be related to myocardial ischemic reperfusion injury.Captoprilenriched cardioplegia offers better myocardial protection effects than cold crystalloid cardioplegia alone.The protective effect may attributed to its effect of maintaining normal NO level through reducing iNOS activity and increasing cNOS activity.