陈旧性心肌梗死兔心室组织重塑及卡维地洛的影响

Effects of carvedilol on ventricular remodeling in rabbits with myocardial infarction

目的:模拟临床陈旧性心肌梗死(OMI),研究长期口服卡维地洛(CVD)对OMI后心室组织重塑的影响。方法:24只家兔按体重随机分为3组,OMI组(8只),结扎冠状动脉左回旋支,喂养3个月;CVD组(8只),手术同OMI组,并于手术当日开始服用CVD 0.33 mg.kg-1.d-1,持续给药至术后共3个月;假手术(Sham)组(8只),手术同OMI组,但不结扎冠状动脉、不服用CVD。3个月后应用全细胞膜片钳技术检测单个心肌细胞膜电容大小。结果:①和Sham组相比,OMI组的全心重、左室重、全心重/体重比值、左心室腔最大内径均显著增加(均P<0.05);CVD组与OMI组相比上述指标、远离梗死区室壁厚度及梗死面积均显著减小(均P<0.05)。②光镜下CVD组与OMI组比较,梗死周边区心肌细胞肿胀、变性程度减轻,淋巴组织浸润减少,心肌间质水肿减轻。仍可见梗死区纤维结缔组织增生,瘢痕形成,肉芽组织增多与存活的肌组织交错分布,脂肪组织浸润。③OMI组心肌细胞的膜电容与Sham组相比明显增大(P<0.05);CVD组心肌细胞的膜电容较OMI组降低(P<0.01)。结论:长期口服CVD可以逆转OMI兔的心室组织重塑。

Objective：To investigate effects of long term treatment with oral carvedilol on ventricular remodeling in HMI. Method：Thirty rabbits were randomly divided into three groups： Old myocardial infarction （OMI） group, ligation of the circumflex coronary artery; carvedilol group, operation the same as OMI group, and admin istration of oral carvedil 0. 33 mg· kg^1 ·d ^1×3m beginning on the day of operation; Sham group, left thoracotomy but no coronary artery ligation. 3 months after surgery, rabbits were harvested, Myocytes were isolated by enzymatic method, using the wholc cell patch clamp technique to record the single cell membrane capacitance. Result：①Whole heart weight （WHW）, WHW body weight, thickness of IRZ ventricular wall and the maximum perimeter of left ventricular chamber in OMI group were all obviously increased compared with those in Sham group, P 〈0. 05;In carvedilol group, thc changcs of above parameters and the infarct size were significantly allevi ated, P 〈0.05.②The tumidness and denaturalization of myocytes , infiltration of lymph tissues and edema of myocardium interstitial in infarction hnrder zone were alleviated under light microscopy in CVD group compared with those in OMI group. Howevcr, fatty tissues infiltration, fibroglia hyperplasia, scar formation and interdigatation between surviving muscle cells and scar tissues were still ohserved. ③The membrane capacitance of myo cytes in CVD group was reduced significantly comparcd with that in OMI group which was larger than that in Sham group （P〈0.05）. Conclusion：Long-term treatment with oral carvedilol may reverse ventricular remodeling.