高血压大鼠心脏中缝管连接蛋白的表达及连接结构观察

Observation on junction structure and expression of gap junction protein in heart of hypertensive rat

目的 为临床高血压心脏病的相关研究提供形态学依据。方法 Dahl盐敏感高血压大鼠于生后 5w开始喂 8%高盐饲料 ,分别于 9、1 1、1 3周龄处死 ,采用透射电镜及免疫组化方法对大鼠心肌细胞的连接结构及缝管连接蛋白 Cx43、Cx40的含量进行研究。结果 心肌细胞的连接结构闰盘似山峰样 ,台阶消失 ,缝管连接位于突起之间 ;实验组 Cx43含量较相应对照组显著减少 (9周龄 P<0 .0 5;1 1、1 3周龄 P<0 .0 1 ) ,分布紊乱 ;Cx40含量在早期 (9周龄 )时显著减少 (P<0 .0 1 ) ,随后显著增加 (P<0 .0 1 )。结论 缝管连接分布的紊乱及 Cx43含量的下降可能在高血压心脏病心律失常的发生上起了重要作用 ,而 Cx40含量增加可能是增加传导速度的一个补偿机制。

Objective To provide morphological data for studies on hypertensive heart disease.Methods Dahl salt sensitive rats were fed with food containing 8% high salt since 5 weeks old.The hearts were havested when the rats were 9?11?13 weeks old and the age-matched samples were seen as control(n=6).The ultrastructure of intercellular junction was shown by transmission electron microscopy and the expression of gap junction protein Cx43?Cx40 was studied by immunohistochemistry.Results Intercalated disk appeared peaks of mountain and gap junction located between projections;There was a significant reduction in Cx43 protein level in different ages compared with control and its distribution became disorder.There was a significant decrease in Cx40 protein level at 9 week old and then significant increase at 11?13 week.Conclusions The reduced expression of Cx43 and its disorder may contribute to the genesis of arrhythmias in hypertensive heart disease.The increased expression of Cx40 may be a compensatory mechanism to increase conduction velocity.