心肌连接蛋白Cx43在冠心病心肌梗死病例中的表达

目的:观察冠心病猝死伴心肌梗死时缝隙连接蛋白43(connexin 43,Cx43)的分布特征,探讨Cx43在冠心病伴心肌梗死的变化规律及其诊断意义。方法:运用免疫组化和图象分析技术,观察实验组冠心病猝死伴心肌梗死者心室肌梗死区、梗死区边缘和非梗死区Cx43分布情况。结果:冠心病猝死伴心肌梗死患者中不同心肌部位的缝隙连接蛋白Cx43阳性表达差异性较大,部分梗死中心区Cx43已完全消失,而部分梗死中心区Cx43有极少部分蛋白发生了重新分布;在梗死边缘带绝大部分Cx43已消失,只有极少数Cx43分布于心肌细胞侧-侧相接处;在非梗死处心肌基本正常,但细胞闰盘的Cx43阳性严重崩解破坏,而重新分布于细胞侧-侧相接处。结论:冠心病猝死伴心肌梗死时心肌梗死病灶及其邻近区域Cx43的数量及分布的高度不均一性是发生猝死性心律失常的结构基础,同时表明在诊断冠心病猝死伴心肌梗死时,脱磷酸化Cx43具有非常重要的诊断价值。

Expression of gap junction connexin 43 in coronary artery disease with myocardial infarction

Objective: To observe the characteristics of distribution of Cx43 in sudden coronary death(SCD) with myocardial infarction for the rule of changes and diagnostic purpose.Methods: Immunohistochemiscal and image analytic techniques were used to investigate the expression of myocardial Cx43 in ventricular infarction,border and non-infarction region in experimental group(SCD with myocardial infarction).Results: The distribution of Cx43 gap junction was markedly observed in different regions.Cx43 was not found in the necrotic zone in some samples,but with a few proteins distributed in some cells.The Cx43 was totally disappeared in border zone and only a few Cx43 were seen in longitudinally oriented side of the muscle cells.In non-infarction region,the Cx43 was also seriously decreased in density and the transversely oriented Cx43 gap junctions were lost much more seriously than the longitudinally oriented ones,though the ventricular muscles seemed normal.Conclusion: Expression of gap junction Cx43 is characterized markedly by inhomogeneity in distribution and density in heart of SCD with myocardial infarction,which accounts for the fatal arrhythmia.Also the experiment shows that Cx43 dephosphorylation is valuable in diagnosis of this disease.