卡维地洛对连接蛋白43的分布及数量的影响

Effect of carvedilol on distribution and expression of connexin43

目的观察卡维地洛对心肌梗死边缘区Cx43分布的影响。方法36只家兔随机分为梗死组,卡维地洛组,假手术组,每组12只。梗死组和卡维地洛组开胸结扎冠状动脉左前降支,假手术组不结扎。所有家兔普通饲料喂养,卡维地洛组另给予卡维地洛5mg·kg^(-1)·d^(-1)。12周后观察:(1)共聚焦激光显微镜观察梗死边缘区Cx43的分布,(2)Werstern Blot检查梗死边缘区Cx43的蛋白表达。结果(1)共聚焦激光显微镜下观察心肌梗死组Cx43荧光斑的形态相对粗乱,呈现不均一分布;卡维地洛组Cx43的荧光分布改变较少,不均一分布的程度较心肌梗死组减轻;心梗组的Cx43相对密度显著低于卡维地洛组;[(0.16±0.06)%vs(0.32±0.11)%,P<0.05];(2)Werstern Blot检查梗死组Cx43及卡维地洛组较假手术组减少,但卡维地洛组的Cx43表达较心肌梗死组增多[(0.89±0.28)vs(0.67±0.32),P<0.05]。结论卡维地洛可以引起Cx43的再分布,增加心肌梗死后Cx43蛋白的表达,这可能是其较减少心肌梗死后室性心律失常的原因之一。

Objective To observe the effect of carvedilol on the expression of Cx43 in rabbits with myocardial infarction and its association with ventricular arrhythmia. Method Thirty-six rabbits were randomly divided into three groups in equal number （n = 12）, namely, myocardial infarction （MI） group, carvedilol group and sham MI group. Rabbits of carvedilol group were administered with carvedilol 5 mg kg^-1·d^-1 after MI induced, while no carvedilol was administered to the MI group. The following observations were made ： （ 1 ） Cx43 density of the epicardial border zone measured by quantitative immnuoconfocal laser scanning, and （2） cx43 protein expression analyzed by western blot. Results （ 1 ） Under immunoconfocal laser microscope, the relative density of Cx43 was （0.16 ± 0.06）% in the infarction group and was （0.32±0.11）% in the sham MI group [ （0.68 ± 0.15） %, both P 〈 0.05], but the level of Cx43 in the carvedilol group was significantly higher than that in the myocardial infarction group （ P 〈 0.05 ）. （2） By western blot analysis, the carvedilol group again had higher Cx43 protein expression than the infarction group [ （0.89 ± 0.28） vs （0.67 ±0.32, P 〈 0.05） ] as well. Conclusions Carvedilol may increase the expression of Cx43 protein after myocardial infarction , and this may contribute to its anti-arrhythmic effect.