摘要目的 观察重症急性胰腺炎(SAP)大鼠肠组织中高迁移率族蛋白B1 (HMGB1)表达对肠黏膜上皮细胞紧密连接occludin蛋白表达的影响.方法 逆行胰胆管注射5％牛磺胆酸钠制作SAP模型.健康Wistar大鼠随机(随机数字法)分为对照组、SAP组、二硫代氨基甲酸吡咯烷(PDTC)处理组.测定血淀粉酶(AMY)、内毒素(LPS)及D-乳酸水平；光镜下观察胰腺和肠组织的病理变化；免疫组织化学法观察occludin分布和表达的变化；RT-PCR法检测大鼠肠组织中HMGB1的表达水平；Western blot法检测大鼠肠组织中HMGB1及occludin蛋白的表达水平.采用SPSS 13.0统计分析软件进行处理,P＜ 0.05为差异具有统计学意义.结果 在建模后24 h,SAP组大鼠血浆LPS及D-乳酸水平明显高于对照组,提示肠屏障通透性明显增加；PDTC处理组大鼠血浆LPS及D-乳酸水平明显低于SAP组(P＜0.05).SAP组大鼠肠组织HMGB1表达水平较对照组明显升高,而occludin蛋白的表达较对照组下降；PDTC组大鼠肠组织HMGB1表达水平明显低于SAP组,occludin水平较SAP组升高(P＜0.05).结论 SAP时,大鼠肠组织内HMGB1表达升高,通过降低occludin蛋白表达,来增加肠黏膜屏障通透性；PDTC可抑制HMGB1表达,上调occludin蛋白表达,改善肠黏膜屏障通透性.

abstractsObjective To observe the effect of high mobility group box-1 protein (HMGB1) on the expression of intestinal epithelial tight junction protein occludin in murine severe acute pancreatitis (SAP).Methods Rat SAP model was estabilished by retrograde injection of 5 ％ sodium taurocholate into choledochopancreatic duct.Healthy wistar rats were divided randomly (random number) into three groups:control group,SAP group,pyrrolidine dithiocarbamate (PDTC) therapy group.Levels of plasm amylase,lipopolysaccharide (LPS) and D-lactate were determined.The changes of morphological damage of pancreasand intestinal tissues were observed by microscopy.The distribution and expression of occludin protein were observed by SP immunohistochemistry. The mRNA expression of HMGB1 in the intestinal mucosa was detected by reverse-transcription polymerase chain reaction (RT-PCR).The expressions of HMGB1 and occludin were determined by western blotting. One-way analysis of variance was performed with SPSS Windows 13.0 statistical analysis software,and a difference was accepted as significant if P ＜ 0.05.Results In comparison with the other two groups,levels of plasma LPS and D-lactate in SAP group increased markedly at 24 h after operation,which indicated that the penetrability of intestinal mucosal barrier increased (P ＜ 0.05 ). The expression of HMGB1 in the intestinal mucosa of SAP group increased significantly compared with control group (P ＜ 0.05).Whereas,the expression of occludin was significantly lower than control group (P ＜0.05).Compared with SAP group,the expression of HMGB1 was lower and the expression of occludin was higher in PDTC group ( P ＜ 0.05).Conclusions The over-expression of HMGB1 could down regulate the expression of occludin in intestinal tissues of SAP rats,and thus mediate an increase in penetrability of intestinal mucosal barrier.As PDTC inhibited the expression of HMGB1,the expression of occludin protein was up-regulated and the function of intestinal mucosal barrier was improved.