禁食降低肠黏膜屏障的形态学观察及对肠道细菌易位的影响

目的 ]观察禁食对肠黏膜屏障功能的影响。 方法 ]制备小鼠及大鼠禁食 (4 8h)模型 ;取小鼠空肠和结肠肠壁组织 ,分别制备光镜及电镜标本 ,观察肠黏膜形态学变化 ;取大鼠肠系膜前淋巴结 ,细菌培养 4 8h后观察菌落生长情况。 结果 ]光镜下禁食组与对照组空肠相比 ,肠壁变薄 ,肠绒毛短细 ,间距变宽 ,肠黏膜上皮细胞严重缺损 ,肠组织有淤血及出血现象。结肠无明显变化。电镜下禁食组空肠和结肠与对照组相比均可见微绒毛缩短 ,数量减少 ,但紧密连接无明显变化。大鼠禁食组肠系膜前淋巴结细菌易位率为 7/ 8,较对照组 2 / 8明显升高 (P <0 .0 5 )。 结论 ]禁食可降低肠黏膜机械屏障进而影响免疫屏障。

Change of intestinal barrier after fasting in animals: Observations of morphology and bacteria translocation

To observe change of intestinal barrier after fasting for 48 hours in mice and rats. Morphological changes were observed under light microscopes (LM) and electrical microscopes (EM), and change of bacteria translocation was measured by bacterial culture after fasting for 48 hours. Compared to the control group, the intestinal wall became thinner, the intestinal villi became shorter and the interspace between the villi became wider in jejunum under LM in fasting group, but not colon, and there were congestion and hemorrhage in submucosal layer in the microvilli of fasting anrwals were shorter,than that of control,but no distinct differences of tight junction were observed in jejunum and colon under EM. The bacterial translocation rate of the experimental group was significantly higher than that of the control group ( P <0.05, n =8). Conclusions] The intestinal mechanical barrier and immunological barrier could be damaged due to fasting.