细胞凋亡在体外循环大鼠肠黏膜屏障功能障碍中的作用

Role of Apoptosis in the Gut Mucosal Barrier Dysfunction in Rats with Cardiopulmonary Bypass

目的 探讨细胞凋亡在大鼠体外循环 (CPB)早期肠道黏膜屏障功能障碍中的作用。方法 建立大鼠CPB模型。分别对CPB组、假手术组 (SO)和正常组 (N)大鼠于术后 3、6、12、2 4h取回肠末端黏膜进行光镜、电镜观察 ,并用TUNEL方法研究肠上皮细胞凋亡。结果 CPB组大鼠除了 2 4h时相点光镜下观察发现肠黏膜上皮细胞脱落外 ,其它时相点肠粘模均保持完整 ,电镜观察可见CPB各时点均可见典型凋亡细胞 ;TUNEL法显示CPB组各时相点肠黏膜上皮细胞凋亡指数较SO组显著增加 (P值 <0 0 1) ,并于CPB结束后 6h达到峰值 ,凋亡细胞主要分布在肠黏膜隐窝部。结论 大鼠CPB后早期肠黏膜上皮细胞凋亡明显增加 ,上皮细胞凋亡增加可能是CPB后肠黏膜屏障功能障碍的病理生理基础。

Objective To investigate the role of cell apoptosis in the gut mucosal barrier dysfunction in rats undergoing cardiopulmonary bypass(CPB) . Methods The rat model of CPB was set up. The rats were divided into CPB group, sham operation(SO) group and normal control group. The morphological changes of ileum mucosal tissues were observed by microscope and electron microscope at 3h, 6h, 12h and 24h after operation, respectively. The apoptotic index of gut mucosal epithelial cells was measured with TUNEL method. Results Gut mucosal morphology was normal in CPB group at 3h, 6h and 12h after operation, but gut mucosal epithelial desquamation occurred at 24h after operation. Typical apoptotic cells could be seen with electron microscope in CPB group at every time point. Apoptotic index of gut mucosal epithelial cells significantly increased in CPB group at every time point compared with SO group, and peaked at 6h after operation. Apoptotic cells were mostly located in the gut crypt. Conclusion The data suggested that the apoptosis of intestinal epithelial cells significantly increased at early stage of post-CPB in rats, which might contribute to gut mucosal barrier dysfunction.