缺氧缺血性脑损伤大鼠小肠黏膜屏障功能变化观察

Intestinal mucosal barrier function changes in rats with hypoxic-ischemic brain damage

目的观察缺氧缺血性脑损伤(hypoxic -ischemic brain damage,HIBD)大鼠小肠黏膜屏障功能的变化,并探讨其机制。方法 90只SD大鼠随机分成正常组、假手术组和模型组,每组30只。模型组制备HIBD模型,假手术组大鼠仅予颈总动脉分离,正常组大鼠不予手术。分别于造模后第1、7、21天取三组大鼠,摘除眼球取血,处死后取回肠末端肠段(每个时间点10只)。ELISA 法检测各组大鼠眼球血清D-乳酸(D-LA)、肠脂肪酸结合蛋白(iFABP)。肠黏膜染色后显微镜下观察并记录小肠绒毛高度和隐窝深度;免疫荧光染色法测算肠黏膜跨膜蛋白Occludin、紧密连接蛋白ZO-1的积分光密度IOD值。结果 与正常组、假手术组比较,造模后第1、7、21天HIBD 组眼球血清D-LA、iFABP水平均升高,小肠绒毛高度和隐窝深度均降低,回肠末端Occludin、ZO-1的IOD值均降低( P 均< 0.05 )。造模后各时段HIBD组眼球血清D-LA、iFABP水平、小肠绒毛高度和隐窝深度及回肠末端Occludin、ZO-1的IOD值间比较差异均无统计学意义( P 均>0.05)。结论 HIBD大鼠眼球血清D-LA、iFABP水平升高,回肠末端肠绒毛高度和隐窝深度降低,可能与回肠末端组织Occludin、ZO-1表达降低有关。

Objective To investigate the changes of intestinal mucosal barrier function in rats with hypoxic-ischemic brain damage (HIBD)and its mechanisms. Methods Ninety rats wererandomly divided into the control group and sham operation group,and HIBD group. The HIBD models were prepared in the HIBD group, and the rats in the sham operation group only received the separation of the common carotid artery, and the rats in the control group were not treated.Rats were sacrificed at 1, 7, and 21 d after modeling and the blood and distal ileum were collected. The intestinal fatty acid binding protein (iFABP) and D-lactic acid(D-LA) in plasma were detected to study the intestinal mucosal barrier permeability by ELISA. The expression of tight junction protein (Occludin, ZO-1) in distal ileum was analyzed by immunofluorescence staining as well as the IOD of ZO-1. Results Compared with the control group and sham operation group, the levels of iFABP and D-LA in plasma increased, while the height of intestinal villi, the crypt depth and the expression of Occludin and ZO-1 in distal ileum decreased in the HIBD group at 1, 7, and 21 d after modeling (all P <0.05). There was no statisticaldifference between the control group and sham operation group (all P >0.05). No significant differences were found in the above indicators (the level of iFABP and D-LA, the height of intestinal villi, the crypt depth and the expression of Occludin and ZO-1) at different time in the HIBD group (all P >0.05). Conclusion The levels of iFABP and D-LA increasein the serum of HIBDrats, while the height of intestinal villiand the crypt depth decrease, which may be associated with the decreased expression of Occludin and ZO-1 in distal ileum.