建立术后肠梗阻大鼠模型的新方法及评价

A new method of modelling postoperative ileus in rats and its evaluation

目的研究不同造模方法对SD大鼠术后胃肠动力及血清IL-6、TNF-α水平的影响,建立操作便捷、能真实模拟临床腹部手术术后肠梗阻、重复性好的动物模型。方法将60只SD大鼠采用随机数字表法分为模型A、B、C、D组、假手术组和空白组,每组10只。模型A组以湿棉签擦拭小肠3次;模型B组切除部分盲肠;模型C组切除部分盲肠+湿棉签擦拭小肠1次;模型D组切除部分盲肠+小肠中部离断后再吻合;假手术组开腹后静置20 min关腹;空白组不予手术处理。术后24 h,采用ELISA法检测血清IL-6、TNF-α水平;计算胃肠推进率及胃残留物质量;对小肠病理切片进行观察;Pearson相关分析胃肠推进率与血清IL-6、TNF-α水平的相关性。结果术后24 h,空白组IL-6、TNF-α水平均明显小于模型A、B、C、D组(均P<0.01);模型C、D组IL-6、TNF-α水平均明显高于模型A、B组、假手术组、空白组(均P<0.01)。术后24 h,空白组胃肠推进率均明显高于模型A、B、C、D组,胃残留物质量均明显低于模型B、C、D组(均P<0.01);模型C、D组胃肠推进率均明显低于模型A组、假手术组、空白组,胃残留物质量均明显高于模型A组、假手术组、空白组(均P<0.01),其中模型C组胃肠推进率明显低于模型A组(P<0.01)。模型A、B组的肠黏膜坏死、脱落;模型C、D可见黏膜坏死、脱落并有大量炎症细胞浸润;空白组及假手术组肠黏膜上皮排列有序,绒毛结构清晰,组织结构正常,未见损伤。大鼠胃肠推进率与血清IL-6水平呈极强负相关(r=-0.85,P<0.01),与血清TNF-α水平呈强负相关(r=-0.79,P<0.01)。结论部分盲肠切除术+小肠擦拭法成功模拟了术后肠梗阻,操作简便,适用于SD大鼠术后肠梗阻造模;且术后肠梗阻模型大鼠的胃肠动力与血清IL-6、TNF-α水平呈反相关。

Objective To establish a animal model of postoperative ileus(POI)in rats.Methods Sixty SD rats were divided into 6 groups with 10 animals in each group.No surgical intervention was given to blank group,the abdomen was opened and closed in the sham operation group.In model group A,the small intestine was wiped three times with normal saline cotton swab,in model group B,part of the cecum was excised and ligated,in model group C,part of the cecum was excised,and then the small intestine was wiped once with normal saline cotton swab,in the model group D,part of the cecum and the middle part of the small intestine were excised,and then the intestine was anastomosed.The serum IL-6 and TNF-αwere measured,the gastric residues were weighted,the intestine samples were taken for pathological examination 24 h after the operation.Results The weight of gastric residue in model groups was great than that in blank group(P<0.01),the weight of gastric residues in model B,C,D group was great than that in model A group(P<0.01).The gastrointestinal propulsion rate in model groups was lower than that in blank group(P<0.01),the gastrointestinal propulsion rate in model B,C,D group was lower than model A group(P<0.01).The serum IL-6 level in model groups was higher than that in blank group,the IL-6 levels in Model C,D groups were higher than those in model A,B group(P<0.05).The serum TNF-αlevels in model groups were higher than that in blank group(P<0.01),TNF-αlevels in model C,D group were great than those in model A,B group(P<0.01).The gastrointestinal propulsion rate was negatively correlated with IL-6 and TNF-α.Pathological examination of small intestinal wall showed no abnormality in the blank group and sham operation group.Mucosal layer was exfoliated and necrotic in each model groups,and inflammatory cell infiltration was found in model C,D groups.Conclusion Partial cecectomy and small intestine swabbing can be used for modeling postoperative ileus in rats.Gastrointestinal motility is negatively correlated with serum IL-6 and TNF-αin POI Rats.