严重多发伤并急性胃肠损伤家兔的肠道黏膜损伤严重程度及α7烟碱型乙酰胆碱受体的变化

Severity of intestinal mucosal injury and change inα7-nicotinic acetylcholine receptor in rabbits with severe multiple injuries and acute gastrointestinal injury

目的:探究严重多发伤并急性胃肠损伤(AGI)家兔的肠道黏膜损伤严重程度及α7烟碱型乙酰胆碱受体(α7-nAChR)的变化。方法:使用自制重力小型牵引式对(侧)撞机来模拟交通意外致伤以构建严重多发伤家兔模型;创伤严重程度评分(ISS)评估家兔创伤程度;AGI评分评估家兔AGI程度;ELISA法检测血浆二胺氧化酶(DAO)、内毒素及血清TNF-α含量;高压液相色谱法检测尿液乳果糖(L)、甘露醇(M)含量,并计算L/M;平板计数法检测家兔肠道细菌移位情况;HE染色及透射电镜分别观察小肠组织病理变化及超微结构损伤情况;免疫组化法及Western blot检测小肠组织α7-nAChR表达情况。结果:造模12 h后,AGI分级:Ⅰ级40只,Ⅱ级25只,Ⅲ级11只,Ⅳ级4只;与T0比较,T1、T2、T3家兔血浆DAO及内毒素、尿液L/M及血清TNF-α含量、肠道细菌移位率、肠道病理损伤程度随时间的推移依次显著升高(P<0.05),小肠组织α7-nAChR表达随时间的推移依次显著降低(P<0.05)。结论:严重多发伤家兔于早期便出现肠道功能损伤、肠道菌群移位及肠黏膜屏障功能损伤,这可能与α7-nAChR表达降低有关。

Objective:To explore the severity of intestinal mucosal injury and the change inα7-nicotinic acetylcholine receptor(α7-nAChR)in rabbits with severe multiple injuries and acute gastrointestinal injury(AGI).Methods:A self-made small gravity towed(side)collider was used to simulate traffic accident injuries to build a rabbit model with severe multiple injuries;the Injury Severity Score(ISS)was used to evaluate the trauma degree of rabbits;AGI score was used to assess the degree of AGI in rabbits;ELISA method was used to detect plasma diamine oxidase(DAO),endotoxin and serum TNF-α;high pressure liquid chromatography was used to detect urine lactulose(L)and mannitol(M)contents,and calculated L/M;plate counting method was used to detect the intestinal bacterial translocation of rabbits;HE staining and transmission electron microscope were used to observe the pathological changes and ultrastructural injury of the small intestine;immunohistochemistry and Western blot were used to detect the expression ofα7-nAChR in small intestine tissue.Results:Twelve hours after the model was made,AGI classification showed:40 cases of classⅠ,25 cases of classⅡ,11 cases of classⅢand 4 cases of classⅣ;compared with T0,the plasma DAO and endotoxin,urine L/M,serum TNF-αcontent,intestinal bacterial translocation rate,and intestinal pathological injury degree of rabbits at T1,T2,T3 increased significantly over time(P<0.05),the expression ofα7-nAChR in the small intestine tissue decreased significantly over time(P<0.05).Conclusion:Rabbits with severe multiple injuries have intestinal dysfunction,intestinal flora translocation and intestinal mucosal barrier function injury in the early stage,which may be related to the decrease ofα7-nAChR expression.