缺血再灌注大鼠心肌细胞钙黏蛋白的表达

Expression of cadherin in myocardial cells of rats with ischemia reperfusion

目的:分析N-钙黏蛋白在缺血再灌注大鼠心脏中的表达分布特征与心肌结构功能的关系。方法:实验于2004-10在新乡医学院形态实验室完成。①选择出生后3～5个月的健康雄性Wistar大鼠27只。随机分为3组,每组9只:正常对照组、心肌缺血组和心肌缺血再灌注组。②麻醉大鼠,暴露心脏,在肺动脉圆锥与左心耳间,离冠状动脉起始约2mm处穿线进行结扎,造成急性心肌缺血,分别做缺血30,45,60min的不同处理(心肌缺血组),心肌缺血再灌注组同心肌缺血组处理,在心肌缺血30min后松开结扎线,再灌注30和60min。正常对照组只做穿线不作结扎。③模型制作完毕,处死大鼠,迅速取心脏病变部位,制成常规石蜡包埋切片,以备组织学检查。应用免疫组化方法检测各组大鼠的心肌细胞钙黏蛋白的表达。结果:大鼠27只均进入结果分析。正常对照组细胞N-钙黏蛋白免疫标记呈阶梯形典型的集中分布于心肌细胞成熟的端闰盘处。镜下观察缺血30和45minN-钙黏蛋白的表达与正常对照组比较,差异不明显;缺血60min后,心肌细胞分布混乱,肌膜出现破损,钙黏蛋白在心肌细胞闰盘处的表达减少。缺血30min,再灌注30和60min后,心肌细胞端闰盘处N-钙黏蛋白的表达与正常对照组比较,差异也不明显。结论:①N-钙黏蛋白的降解和分布模式的改变是急性缺血后心肌在分子水平上发生的最初重构,也是心肌细胞间机械偶联失常和收缩功能异常的解剖学基础。②短时间的缺血再灌注可使心肌代谢迅速改善并恢复正常,N-钙黏蛋白的表达变化反映了心肌细胞结构和功能的改变。

AIM： To investigate the relation between the distribution of N-cadherin expression in myocardial tissues and myocardial structure and function of rats with ischemia reperfusion. METHODS： The experiment was carried out in the mophologic laboratory of Xinxiang Medical College in October 2004.①Twenty-seven healthy male Wistar rats with 3 to 5 months old were randomly divided into three groups with 9 rats in each group： control group, ischemia group and ischemia-reperfusion group. ②After anesthesia and heart exposure, the ligation was conducted at about 2 ram from the coronary artery, between pulmonary infundibulum and left aurcle to form acute myocardial ischemia for 30, 43, 60 minutes respectively to establish the models of myocardial ischemia. With the same way, the ligature was loosened up after 30 minutes myocardial ischemia and then the reperfusion was performed for 30 and 60 minutes to make the models of myocardial ischemia-reperfusion. The control group was treated without ligation. ③ After the models were established, the rats were killed to take out heart tissue and make sections after routine paraffin imbedding, which was prepared for the histological examination. The immunohistochemical method was used to monitor the N-cadherin expression in myocardial cells of rats. RESULTS： All 27 rats were involved in the result analysis. In the control group, the immunolabel N-cadherin were distributed in the end-intercalated disk of myocardium. The N-cadherin expression of ischemia 30 minutes and 40 minutes had no significant differences compared with the control group; after 60 minutes of ischemia, the cardiac muscle cells were distributed disarderly with myolemma injury, and the N-cadherin expression decreased in the intercalated disk of myocardium. The N-cadherin expression of ischemia 30 minutes, reperfusion 30 minutes and 60 minutes also had no significant differences compared with the control group. CONCLUSION： ① The changes of the degradation and distribution patterns of the N-cadherin expression are the initial reconstruction at the molecule level, which are also the anatomy basic of abnormity mechanical couple and function of contraction between myocardium cells. ②Short phase ischemia reperfusion can rapidly improve myocardium metabolism to recover the normal level. Meanwhile, the changes of the N-cadherin expression reflect the changes of myocardial structure and function.