肠缺血/再灌注时卡巴胆碱对肠上皮细胞凋亡的影响

目的研究肠缺血/再灌注(I/R)时卡巴胆碱对肠上皮细胞凋亡的影响及可能机制。方法雄性Wistar大鼠,戊巴比妥钠腹腔麻醉,结扎肠管造成长约8cm肠袋,采用夹闭肠系膜上动脉(SMA)阻断血流45min后恢复血流的方法,制备肠I/R损伤模型。将动物按随机数字表法分为假手术组(n=40)、I/R模型组(n=40)和卡巴胆碱组(n=40)。卡巴胆碱组在阻断血流的同时向肠袋内注射卡巴胆碱(0.1mg/kg),I/R模型组给予等量生理盐水。分别在再灌注0、30、60、120和240min时,采用病理学方法按Chiu's评分观察肠上皮细胞损伤;原位末端缺刻标记法(TUNEL)检测肠上皮细胞凋亡指数的变化;免疫组化法检测肠上皮细胞凋亡相关半胱氨酸天冬氨酸特异性蛋白酶(caspase-3)和Bcl-2蛋白表达的变化。结果与I/R模型组比较,卡巴胆碱组肠上皮细胞病理学变化较轻,凋亡指数明显降低,caspase-3阳性肠上皮细胞数明显减少,而Bcl-2阳性肠上皮细胞数明显增加(P均<0.01)。结论卡巴胆碱能抑制I/R时肠上皮细胞caspase-3表达,增加Bcl-2表达,减少肠上皮细胞的凋亡。

Effects of carbachol on apoptosis of intestinal epithelial cells after gut ischemia/reperfusion in rat

Objective To investigate the effects of carbachol on apoptosis of intestinal epithelial cells in rats after gut ischemia/reperfusion (I/R).Methods A jejunal sac was formed in Wistar rats.The superior mesenterie artery (SMA) was occluded for 45 minutes followed by 240 minutes of reperfusion. Immediately after occlusion of SAM blood flow,either 0.1mg/kg of carbachol or same amount of 0.9% normal saline was injected into the jejunal sac.Animals were randomized into three groups (each n=40): sham operation,I/R normal saline injection (I/R model) and I/R carbachol injection (0.1 mg/kg,Ca). The pathological changes in gut epithelial cells were assessed by Chiu's scores.The apoptosis index of intestinal epithelial cell was determined with terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling(TUNEL)staining.Expressions of caspase-3 and Bcl-2 in intestinal epithelial cells were assayed by immunohistochemistry method.All measurements were done at 0,30,60,120 and 240 minutes after reperfusion.Results The pathological injuries were less severe in Ca group than those in I/R model group.Apoptosis index of intestinal epithelial cell and expressions of caspase-3 were significantly decreased, while the expressions of Bcl-2 increased dramatically (all P<0.01) after I/R in Ca group compared with those in I/R model group,especially at 120 minutes after reperfusion.Conclusion Enteral administration of carbachol can inhibit apoptosis of intestinal epithelial cells in rats after gut I/R injury.