快速进入高海拔地区对大鼠小肠Cajal间质细胞和缝隙连接蛋白43的表达影响

摘要

目的 通过观察快速进入高海拔地区大鼠小肠动力紊乱发生过程中,小肠Cajal间质细胞(interstitial cell of Cajal, ICC)与缝隙连接蛋白43(Connexin 43,Cx43)的表达变化,探讨其发病机制.方法 30只SD雄性大鼠以低海拔地区(海拔400 m)为对照组,并以进入高海拔地区(海拔4 300 m)后的时间节点依次分为3 d和14 d组,每组10只.测定各组大鼠小肠电活动数据,应用电子显微镜观察ICC的微观结构变化,应用双重免疫荧光组织化学染色法观察同区域ICC和Cx43的表达变化.结果 大鼠快速进入高海拔地区后,其小肠电波幅及波频于3 d组下降到最低点(P<0.05).使用双重免疫荧光组织化学染色法同步标记小肠电起搏区ICC和Cx43,所得免疫荧光强度同样在高海拔地区3 d组表达下降到最低点(P<0.05).结论 ICC细胞缝隙连接受损及其与Cx43的表达异常导致ICC细胞间、ICC与消化道平滑肌(smooth muscle cell, SMC)间物质及电信号传递障碍,可能是快速进入高海拔地区胃动力紊乱形成的重要机制之一.%Objective To investigate the role of interstitial cell of Cajal (ICC) and the gap junction Connexin 43 (Cx43) in small intestine dynamic disorders in high altitude exposed rats.Methods Thirty SD male rats were divided into 3 groups, each group contained 10 rats.Control group was located in low altitude (Xi'an, 400 m).On the basis of duration time after entering high altitude (4 300 m), rats were divided into 3 days group and 14 days group.The rats' small intestine electrical activity was measured in different groups.Electron microscope was applied to observe the physiological ultrastructure of ICC, and the immunofluorescence staining was applied to observe the expressions of ICC and Cx43 in small intestine.Results The amplitude and frequency of small intestine electrical activity of rats were the lowest in high altitude 3 days group (P<0.05).The gap junctions and organelles of ICC were reduced, and apoptotic bodies were observed in 3 days group by electron microscope.The expressions of ICC and Cx43 were also observed to be the lowest in high altitude 3 days group (P<0.05).Conclusion The absence of ICC and Cx43 expressions, and the destruction of the gap junction may induce the dysfunctions of intercellular substance exchange and communication transmission among ICC, ICC and smooth muscle cell, which may partly be responsible for the pathogenesis of small intestine dynamic disorders in high altitude exposed rats.