贝那普利对陈旧性心肌梗死大鼠心室肌Cx43重构的影响

Effect of Benazepril on Connexin43 Remodelling Reduced by Old Myocardial Infarction

【目的】观察贝那普利对陈旧性心肌梗死大鼠心室肌缝隙连接蛋白43（connexin43，Cx43）重构的影响，探讨其防治心肌梗死时室性心律失常的可能机制。【方法】①陈旧性心肌梗死大鼠模型制备：结扎大鼠左冠状动脉前降支造成心肌梗死，术后恢复4周；②将24只大鼠随机分为三组：对照组、陈旧性心肌梗死组（Ⅰ组）、贝那普利＋陈旧性心肌梗死组（Ⅱ组）；③免疫细胞化学法检测Cx43含量和分布。【结果】免疫细胞化学结果显示，梗死中心区Cx43完全消失。与对照组心梗边缘带相比，Ⅰ组和Ⅱ组心室组织Cx43分布不均一，含量降低；与Ⅰ组相比Ⅱ组心室Cx43含量增加、分布不均一的程度减轻。与对照组非缺血区相比，Ⅰ组Cx43含量降低，Ⅱ组Cx43含量增加。【结论】①陈旧性心肌梗死时心室肌Cx43的数量和分布呈现高度不均一性，尤其在边缘带。②贝那普利能有效减轻陈旧性心肌梗死所致Cx43的重构。

[Objective] To observe the effect of benazepril on eonnexin 43（Cx43） remodelling in rats with old myocardial infarction and explore its possible mechanism in preventing and curing ventricular arrhythmia. [Methods]The animal model of old myocardial infarction with postoperative recovery lasting 4 weeks was prepared by ligating left anterior descending coronary arteries. Twenty four rats were randomly divided into control group, old myocardial infarction group（Group Ⅰ ） and old myocardial infarction combining with benazepril group（Group Ⅱ ）. The content and distribution of Cx43 were determined by semiquantitative analysis. [Resuits] Immunocytochemical staining revealed that Cx43 was not found in the necrotic zone. In Group Ⅰ , the content of Cx43 in the boundary zone was significantly lower than that in control group, and the distribution of Cx43 was nonuniform. In Group Ⅱ , the change of Cx43 was similar to that in Group Ⅰ when compared with control group, but the level of Cx43 increased more significantly than that in Group Ⅰ, and the alleviation of ununiformity in the Cx43 distribution was observed as well. In non-ischemic zones, there was no significant change in Cx43 density or distribution in Group I and in Group Ⅱ when compared with control group. In Group Ⅱ , the contents of Cx43 in lateral wall and posterior wall of cardiac muscle were significantly higher than those in control group. [Conclusion] There is marked ununiformity in distribution and density of Cx43 in old myocardial infarction, especially in the boundary zone. Benazepril can effectively alleviate Cx43 remodelling induced by old myocardial infarction.