右美托咪定对肠源性脓毒症大鼠肠黏膜屏障的影响及其机制  

Effect of dexmedetomidine on intestinal mucosal barrier in rats with enterogenic sepsis and its mechanism

作　　者：王玥 王建刚 WANG Yue;WANG Jiangang(Department of Anesthesiology,School of Anesthesiology,Shanxi Medical University,Taiyuan 030001,China;Department of Anesthesiology,First Hospital of Shanxi Medical University)

机构地区：[1]山西医科大学麻醉学院麻醉教研室,太原030001 [2]山西医科大学第一医院麻醉科

出　　处：《山西医科大学学报》2022年第6期698-703,共6页Journal of Shanxi Medical University

摘　　要：目的探究右美托咪定(DEX)对肠源性脓毒症大鼠肠黏膜屏障的影响及其机制。方法60只8~9周龄雄性SD大鼠被随机分为脓毒症组、DEX组和对照组,每组20只。脓毒症组和DEX组通过改良盲肠穿刺法建立肠源性脓毒症大鼠模型,DEX组即刻腹腔注射40μg/kg DEX,对照组以及脓毒症组腹腔注射等量0.9%氯化钠。给药24 h后尾静脉采血1.5 ml,采用酶联免疫吸附试验测量血清IL-1β、TNF-α、IL-6水平,HE染色法观察评价大鼠肠黏膜的病理学改变;采用Western blot检测肠道组织Wnt3a蛋白、β-连环蛋白(β-catenin)、细胞周期蛋白(Cyclin D1)以及闭锁蛋白(zonula occludens 1,ZO-1)、闭合蛋白(Occludin)的表达量;并通过免疫组化染色验证Wnt3a蛋白、β-连环蛋白(β-catenin)、细胞周期蛋白(Cyclin D1)的表达。结果ELISA结果显示,脓毒症组血清中IL-1β、TNF-α、IL-6水平与对照组比较显著升高,而DEX组较脓毒症组这3种炎性因子水平显著降低(P<0.01)。HE染色显示脓毒症组大鼠肠道黏膜损伤情况较为严重,而DEX组大鼠肠道黏膜损伤明显改善。Western blot条带灰度值分析,与对照组比较,脓毒症组中Wnt3a、β-catenin及Cyclin D1蛋白的表达量升高明显(P<0.01),ZO-1、Occludin蛋白表达量明显降低(P<0.01);与脓毒症组比较,DEX组Wnt3a、β-catenin及Cyclin D1蛋白表达水平均降低(P<0.01),ZO-1、Occludin蛋白表达量均升高(P<0.01)。免疫组化染色结果中大鼠肠黏膜Wnt3a、β-catenin、Cyclin D1蛋白染色情况与Western blot实验结果相同。结论DEX可通过下调Wnt/β-catenin信号通路降低相关炎症因子IL-1β、TNF-α、IL-6的水平,减轻炎症反应;也可上调紧密连接蛋白ZO-1、Occludin的表达。DEX可能通过这两种机制对肠源性脓毒症大鼠肠黏膜屏障产生保护作用。Objective To investigate the effect and mechanism of dexmedetomidine(DEX)on intestinal mucosal barrier in rats with enterogenic sepsis.Methods Sixty male SD rats aged 8-9 weeks were randomly divided into sepsis group,DEX group and control group,with 20 rats in each group.The rat model of intestinal sepsis was established by modified cecal puncture in sepsis group and DEX group.The rats in DEX group were immediately injected with 40μg/kg DEX,and the rats in control group and sepsis group were injected with the same amount of 0.9%sodium chloride.After 24 h administration,1.5 ml of blood was collected from the tail vein,and the serum levels of IL-1β,TNF-αand IL-6 were measured by ELISA,and the pathological changes of intestinal mucosa were observed and evaluated by HE staining.The expression levels of Wnt3a,β-catenin,Cyclin D1,zonula occludens 1(ZO-1)and Occludin were detected by Western blot.The expression of Wnt3a,β-catenin and Cyclin D1 were confirmed by immunohistochemical staining.Results ELISA showed that the serum levels of IL-1β,TNF-αand IL-6 in sepsis group were significantly higher than those in control group,while the levels of these three inflammatory factors in DEX group were significantly lower than those in sepsis group(P<0.01).The intestinal mucosa injury of septic rats was more serious by HE staining,but the intestinal mucosa injury of rats was improved obviously after DEX treatment.Compared with control group,the expression of Wnt3a,β-catenin and Cyclin D1 in sepsis group was increased significantly(P<0.01),while the expression of ZO-1 and Occludin was decreased significantly(P<0.01).Compared with sepsis group,the expression of Wnt3a,β-catenin and Cyclin D1 was decreased in DEX group(P<0.01),while the expression of ZO-1 and Occludin was increased(P<0.01).The results of immunohistochemical staining of Wnt3a,β-catenin,Cyclin D1 protein in intestinal mucosa of rats were the same as the results of Western blot.Conclusion DEX can reduce the levels of IL-1β,TNF-α,IL-6 by down-regulating Wnt/�

关 键 词：肠源性脓毒症 肠黏膜 右美托咪定 Wnt信号通路 紧密连接蛋白 

分 类 号：R63[医药卫生—外科学]