目的　探讨大鼠心脏连接蛋白 4 3(Cx4 3)表达的增龄变化规律。　方法　应用SP免疫组织化学方法 ,检测 2 1例幼年组、青年组和老年组大鼠心肌细胞Cx4 3的蛋白表达。　结果　 1 Cx4 3主要在心室肌表达。 2 幼年大鼠心室肌的Cx4 3多数已聚集于端闰盘处 ,少数仍呈斑点状散在分布 ,而乳头肌等处的Cx4 3主要分布于细胞表面。青年和老年大鼠的Cx4 3典型地分布于端闰盘处。　结论　Cx4 3的表达因年龄和部位不同均有差异 Objective To investigate the changes of the expression of Cx43 in rats. Methods SP immunohistochemistry was used to detect the protein expression of Cx43 in myocardial cells of 21 neonatal rats, young rats and senile rats. Results 1 Cx4 3 was mainly expressed in ventricular muscle. 2 The majority of Cx4 3 in ventricular muscle of juvenile rats has gathered at the terminal intercalated disc, while a few still distribute in spots. The Cx4 3 in papillary muscle mainly distributes on the cell surface. Cx4 3 in young and old rats is typically distributed at the terminal intercalation disc. Conclusion The expression of Cx4 3 varies with age and location