前列腺素E_1对未成熟心肌缺血-再灌注损伤心肌超微结构变化的影响

Effect of prostaglandin E_1 on ultrastructural change of imm ature myocardial ischemia-reperfusion injury

目的 观察前列腺素 E1 (PGE1 )对未成熟心肌缺血 -再灌注损伤后心肌超微结构变化的影响 ,探讨 PGE1对未成熟心肌的保护作用。 方法 将 2 4只 3～ 4周龄中国大白兔按单纯随机抽样法分为 3组 ,每组 8只。 组 :正常对照组 ; 组 :缺血 -再灌注损伤组 ; 组 :给药组 ,于缺血前静脉注射 PGE1 (10μg/kg)。建立在体心脏缺血 -再灌注损伤模型 ,用 Maclab/8s多功能生理仪监测左心室血流动力学变化及透射电子显微镜观察心肌超微结构的变化。 结果再灌注 6 0分钟后 , 组左心室发展压 (L VDP)恢复率和左心室压力变化速率 (± dp/dtmax)恢复率显著高于 组 (P<0 .0 5 ) ; 组血浆肌酸激酶、乳酸脱氢酶活性低于 组 (P<0 .0 5 ) ; 组心肌组织超氧化物歧化酶 (SOD)活性高于 组(P<0 .0 5 ) ,而 MDA含量低于 组 (P<0 .0 5 )。透射电子显微镜观察可见 组线粒体水肿、破裂明显 ,而 组线粒体损伤较轻。 结论 PGE1 能够提高 SOD活性 ,减轻心肌缺血 -再灌注生成的氧自由基对未成熟心肌及线粒体膜结构的损伤。

Objective To observe the effect of prostaglandin E 1 (PGE 1) on ultrastructural change of immature myocardial ischemia-reperfusio n injury and its protective effect on immature myocardial in rabbits. M ethods Twenty-four rabbits(aged 3 to 4 weeks) were randomly divided into three groups (n=8 each group): GroupⅠ, normal control group; GroupⅡ,ischemia-reperfusion injury group, subjected to 30min occlusion and 60m in reperfusion; GroupⅢ, pretreatment with PGE 1(10μg/kg)before occlus ion. Rabbit hearts were subjected to ischemia-reperfusion. Maclab V/ 8.0 sys tem software were used to measure left ventricular hemodynamics. Myocardial ultrast ructure were examined under tran smission electronic microscope. Results Sixty minutes after r epe rfusion, percent recovery of left ventricular developed pressure(LVDP) and ±dp/ dt max were higher in group Ⅲ than those in group Ⅱ(P<0.05). The ac tivity of lactate dehydrogenase(LDH) and creatine kinase (CK) in plasma were hig her in groupⅡthan those in groupⅢ(P<0.05). The activity of superoxide dism utase( SOD) in myocardium were lower in groupⅡ than that in groupⅢ (P<0.05 ). The content of malondialdehyde(MDA) in myocardium were higher in groupⅡ tha n tha t in group Ⅲ (P<0.05). The myocardial ultrastructural changes were signific ant in groupⅡ,there were significant edema in myocardium and in mitochondria, s evere damage in mitochondria;but there was not so severe in groupⅢ. Co nclusion PGE 1 can elevate the SOD activity and reduce the production of oxygen free radicals thus reduce the injury to immature myocardium and mitoch ondrion.