摘要
【目的】从心肌细胞线粒体改变的角度,比较超极化停跳和去极化停跳(钾停跳)的心肌保护效果。【方法】18只纯种比格犬,体质量8.5～15kg,随机分为实验组和对照组,实验组10例,对照组8例。全麻后建立体外循环模型。阻断主动脉后从主动脉根部灌注停跳液20mL/kg,全心缺血45min后,恢复灌注60min。实验组的停跳液为温血(34℃)尼可地尔(含尼可地尔400滋mol/L),对照组的停跳液为传统的4℃高钾停跳液(含钾22mmol/L),停跳后两组心脏均局部冰敷以保持低温。心脏停跳期间若出现心电活动,则追加停跳液首量的三分之一。在主动脉阻断前、主动脉阻断40min、主动脉开放30min,用活检针穿刺取右室全层心肌行电子显微镜检查,每个标本随机选取6个视野照片,用图象分析系统分析计算线粒体的面积和周长,并计算得出线粒体体积密度、比表面和单位面积线粒体计数。检验水准α=0.05。【结果】两组中各有1例因主动脉阻断不全而被剔除,其它各例在实验中均无须追加停跳液。每组3个时间点之间、两组间线粒体的体积密度(volume-density,V/V)、比表面(Rsv)和单位面积线粒体计数的变化均无统计学意义(P>0.05)。【结论】在我们的实验方案下,超极化停跳和高钾停跳都能有效地保护心肌细胞线粒体,且两种方法具有相似的保护效果。
[Objective] To compare the protective effects of hyperpolarizing arrest and potassium arrest on myocardial mitochondria. [Methods] Eighteen Beggle dogs, weighing 8.5 to 15.0 kg, were randomly assigned to study group (n=10) and control group (n=8). After general anaesthesia with tracheal intubation, a cardiopulmonary bypass model was instituted. Cardioplegia solution (20 mL/kg) was perfused to the aortic root after aortic clamp. Global ischemia lasted 45 min and then reperfusion was started for 60 min. The cardioplegia solution for study group was tepid blood nicorandil (34 ℃, 400 ?滋mol/L of nicorandil), for control group was traditional hyperkalemic Thomas solution (4 ℃, 22 mmol/L of potassium). Topical cooling was applied to the hearts for both groups after asystole achieved in order to keep a hypothermia condition for myocardium during global ischemia. One-third of the first dosage of cardioplegia solution would be perfused to the aortic root whenever there appeared cardiac electric activity during global ischemia. Right ventricle sampls were taken by biopsy needle for electron microscopy before aortic clamp, at 40 min after clamp, and at 30 min after clamp removal. Six views of electron microscopy were randomly chosen and photographed for analysis. Automatic photo analysis system was used to analyze the mitochondria area and circumference, and then the mitochondria volume-density (V/V), ratio of surface to volume (Rsv), as well as mitochondria counts were calculated. Statistic standard α=0.05. [Results] There was one dropout for each group because of insufficient aortic clamp, and no additional cardioplegia solution was needed during global ischemia. There is no significance for V/V, Rsv and mitochondria counts within group among the different time points, and between groups. [Conclusion] With our study protocol, both hyperpolarizing arrest and potassium arrest can effectively protect the myocardial mitochondria during global ischemia, and the two methods have similar protection effects for myocardial mitochondria.
出处
《中山大学学报（医学科学版）》
CAS
CSCD
北大核心
2005年第4期439-442,共4页
Journal of Sun Yat-Sen University:Medical Sciences
基金
广东省自然科学基金资助项目(2003C30602)
广东省医学科学研究基金资助项目(A2000145)
