Matsushita T, Takamatsu T
Department of Pathology and Cell Regulation, Kyoto Prefectural University of Medicine, Japan.
Virchows Arch. 1997 Dec;431(6):453-8. doi: 10.1007/s004280050123.
To investigate the regulation of cell-to-cell coupling in myocardial ischaemia, the three-dimensional expression of connexin43 (Cx43) during experimental ischaemia was examined using a confocal laser scanning microscope. After induction of myocardial infarction in rats, serial optical sections were obtained from the left ventricular myocardium at various times (3 h to 60 days after ligation). The expression of Cx43 was detected immunohistochemically with FITC-labelled anti-rat Cx43 antibody. Fluorescent dots of Cx43 remained along the intercalated disc and decreased in number around the infarct up to 12 h after ligation. Cx43-expression disappeared completely within 48 h after ligation. After day 4, and especially on days 8 and 15 after ligation, the edges of the cardiomyocytes bordering the infarcted area manifested numerous sarcoplasmic tentacles that reacted positively to anti-desmin antibody. Distinct expression of Cx43 was observed extensively on the tentacles, although no cardiomyocytes remained viable around them. By day 60 after ligation, atypical expression of Cx43 had disappeared. These findings suggest that ischaemia induces temporally abnormal expression of Cx43, which might be responsible for abnormal conduction around the infarct.
为研究心肌缺血时细胞间偶联的调节机制，采用共聚焦激光扫描显微镜检测实验性缺血过程中连接蛋白43（Cx43）的三维表达。在大鼠诱导心肌梗死后，于不同时间点（结扎后3小时至60天）从左心室心肌获取连续光学切片。用异硫氰酸荧光素（FITC）标记的抗大鼠Cx43抗体免疫组织化学检测Cx43的表达。结扎后12小时内，Cx43的荧光点沿闰盘保留，但梗死灶周围数量减少。结扎后48小时内Cx43表达完全消失。结扎后第4天，尤其是第8天和第15天，梗死灶周边心肌细胞边缘出现许多对结蛋白抗体呈阳性反应的肌浆触须。在触须上广泛观察到Cx43的明显表达，尽管其周围没有存活的心肌细胞。结扎后60天，Cx43的非典型表达消失。这些发现提示，缺血诱导Cx43出现时间上的异常表达，这可能是梗死灶周围异常传导的原因。
