温血停跳液对兔缺血心肌的保护作用

Protective effect of warm blood cardioplegia on ischemic rabbit myocardium

目的 :探讨温血停跳液对心肌的保护作用。方法 :将 2 4只家兔随机分为 3组 :Ⅰ组 (n=8) ,温血停跳液组 ;Ⅱ组(n=8) ,冷晶体停跳液组 ;Ⅲ组 (n =8) ,温晶体停跳液组。Ⅰ组为实验组 ,Ⅱ、Ⅲ组为对照组。使心肌缺血 1 2 0min。3组均在主动脉阻断时和开放前给予剂量相等的停跳液 ,随后每隔 2 0min灌注一次冷晶体停跳液。主动脉开放 1min,取标本测定冠状窦血中乳酸脱氢酶 1 (LDH1 )、肌酸磷酸激酶 MB(CK MB)、心肌线粒体谷氨酸脱氢酶 (GLDH)及心肌含水量(MWC) ,并观察心肌超微结构改变及线粒体立体学定量分析。结果 :主动脉开放 1min ,冠状窦血中LDH1三组间无显著性差别 (P >0 .0 5 ) ;GLDH ,Ⅰ组显著高于Ⅱ、Ⅲ组(P <0 .0 5 ) ,Ⅱ、Ⅲ组间无显著性差别 (P>0 .0 5 ) ;CK MB ,Ⅰ组显著低于Ⅱ、Ⅲ组 (P <0 .0 5 ) ,Ⅱ、Ⅲ组间无显著性差别 (P >0 .0 5 ) ;心肌含水量 ,Ⅰ组显著低于Ⅱ、Ⅲ组 (P <0 .0 5 ) ,Ⅱ、Ⅲ组间无显著性差别 (P >0 .0 5 )。心肌超微结构 ,Ⅰ组分别低于Ⅱ、Ⅲ组(P <0 .0 5 ,P <0 .0 1 ) ,Ⅱ组低于Ⅲ组 (P <0 .0 5 )。结论 :在主动脉阻断时和开放前应用温血停跳液 。

AIM: To investigate the effect of warm blood cardioplegic solution on myocardial protection. METHODS: Twenty four rabbits were randomly divided into three groups. Immediately after aortic clamping and just before aortic unclamping, the rabbit hearts received warm ( 37 ℃ ) blood cardioplegic solution in group Ⅰ (n=8), cold crystalloid crdioplegic solution in group Ⅱ (n=8), and warm ( 37 ℃ ) crystalloid cardioplegic solution in group Ⅲ (n=8) respectively. During 120 min of ischemia, all hearts were reinfused with cold crystalloid cardioplegic solution every 20 min. Samples were taken 1 min after cross clamp removal to assess lactate dehydro gease1 (LDH1) and creatine phosphonate kinase (CK) in coronary sinus blood, and glutamate dehydrogenase (GLDH) within mitochondrion and myocardium water content. Myocardial biopsies were obtained for electron microscopical study and stereological quantitative analysis of mitochondria. RESULTS: 1 min following aortic unclamping, there were no significant differences among the three groups in LDH1 (P> 0.05 ). GLDH was significantly higher (P< 0.05 ) in group Ⅰ than that in group Ⅱ and Ⅲ, while there was no statistical difference between group Ⅱ and Ⅲ (P> 0.05 ). The value of CK MB was significantly lower (P< 0.05 ) in group Ⅰ than that in group Ⅱ and Ⅲ, and the difference was not significant between group Ⅱ and Ⅲ (P> 0.05 ). Myocardium water content in group Ⅰ was the lowest among the three groups (P< 0.05 ), and no significant difference existed between the latter two groups (P> 0.05 ). Myocardial ultrastructure study showed that group Ⅰ was better protected than the other two groups, and group Ⅱ better than group Ⅲ. Stereological quantitative analysis determined by calculation of mitochondria area density revealed significant differences between the three groups, in which group Ⅰ was lower than group Ⅱ (P< 0.05 ) and group Ⅲ (P< 0.01 ), and group Ⅱ lower than group Ⅲ (P< 0.05 ). CONCLUSION: Warm blood cardioplegic solution, applied at the start and the end of aortic clamping, results in better myocardial protection than does the crystalloid solution used alone.