目的观察连接蛋白43(Cx43)在青壮年猝死综合征(SMDS)者心肌细胞的表达,并探讨其法医学意义。方法筛选法医尸检案例45例,其中SMDS组、冠心病猝死组及对照组各15例。采用免疫组织化学和图像分析技术对不同组别Cx43蛋白在心肌细胞内的表达进行阳性单位(PU)定量检测,分析Cx43蛋白在各组表达的差异。所得数据进行统计学分析。结果 SMDS组心肌Cx43染色明显减弱,阳性着色条带分布不均、深浅不一,有的呈散在颗粒状;冠心病猝死组亦见类似变化;对照组未见明显变化。经统计分析发现,3组心肌细胞内Cx43表达的PU值存在显著性差异(P<0.05)。结论 SMDS死前存在心肌缺血及心电紊乱,应属心性猝死范畴。 Objective To observe the expression of connexins 43 (Cx43) in cardiomyocytes of sudden death syndrome (SMDS) in young adults and to explore its forensic significance. Methods 45 cases of forensic autopsy were screened, including 15 cases of SMDS group, 15 cases of sudden death of coronary heart disease group and control group. Immunohistochemistry and image analysis were used to detect the positive expression of Cx43 protein in cardiomyocytes of different groups. The expression of Cx43 in each group was analyzed. The data obtained for statistical analysis. Results Myocardial Cx43 staining in SMDS group was significantly weakened. The positive staining bands were unevenly distributed in different shades. Some of them were scattered in granular form. Similar changes were observed in sudden death group of coronary heart disease, while no significant changes were found in the control group. After statistical analysis, there was a significant difference (P <0.05) in the PU value of Cx43 expression in three groups of cardiomyocytes. Conclusions The existence of myocardial ischemia and ECG disturbance before death in SMDS should belong to the category of sudden cardiac death.