雷帕霉素对重症急性胰腺炎胰腺损害的保护性作用

Protective effect of rapamycin on pancreatic damage in severe acute pancreatitis

目的探究雷帕霉素对重症急性胰腺炎(severe acute pancreatitis,SAP)大鼠胰腺损害的保护性作用,并进一步阐述其保护机制。方法将90只SPF级雄性SD大鼠随机分为3组,即假手术组(SO组)、SAP组和雷帕霉素组(RAPA组),每组30只大鼠;每组大鼠再随机分为24、36和48 h 3个时点亚组,每个亚组10只大鼠。每组大鼠均行开腹手术,采用逆行胰胆管注射法制备模型,SO组大鼠仅注射0.9%生理盐水,SAP组和RAPA组大鼠注射5%牛磺胆酸钠溶液,且RAPA组在注射5%牛磺胆酸钠前30 min经腹腔注射雷帕霉素。分别于模型制备术后24、36及48 h处死相应亚组存活的大鼠,收集大鼠血清和胰腺组织,采用ELISA法检测血清IL-1β、IL-6及TNF-α含量,采用Western blot法检测胰腺组织中磷酸化的哺乳动物雷帕霉素靶蛋白(p-mTOR)和磷酸化的核糖体S6蛋白激酶1(p-S6K1)的表达水平;胰腺组织行HE染色,光镜下进行病理学改变评分。结果①胰腺组织中p-mTOR和p-S6K1的表达水平:24、36及48 h时,胰腺组织中p-mTOR和p-S6K1的表达水平均是SO组<RAPA组<SAP组,3组间两两比较差异均有统计学意义(P<0.05)。②IL-1β:48 h时,3组的血清IL-1β含量顺序为SO组<RAPA组<SAP组,3组间两两比较差异均有统计学意义(P<0.05);IL-6:36 h和48 h时,3组的血清IL-6含量顺序为SO组<RAPA组<SAP组,3组间两两比较差异均有统计学意义(P<0.05);TNF-α:48 h时,3组的血清TNF-α含量顺序为SO组/RAPA组<SAP组(P<0.05),但SO组和RAPA组比较差异无统计学意义(P>0.05)。③胰腺织病理学评分:24、36及48 h时3组胰腺组织的病理学评分顺序均为SO组<RAPA组<SAP组,3组间两两比较差异均有统计学意义(P<0.05)。④胰腺组织中p-mTOR和p-S6K1的表达水平与胰腺组织的病理学评分均呈正相关(r=0.97,P<0.01;r=0.89,P<0.01)。结论雷帕霉素可以减轻SAP的胰腺损害程度,对胰腺组织具有保护性的作用。

Objective To explore the protective effect of rapamycin on pancreatic damage in severe acute pancreatitis(SAP)and further to explain its protective mechanism.Methods Ninety selected SPF males SD rats were randomly divided into 3 groups:sham-operated group(SO group),SAP group,and rapamycin group(RAPA group),with 30 rats in each group.Then each group of rats were randomly divided into 3 subgroups of 24 h,36 h,and 48 h,10 rats in each subgroup.Rats in each group underwent laparotomy,the model was prepared by retrograde injection of solutions into biliopancreatic duct,rats of the SO group were injected with 0.9%normal saline,rats of the SAP group and RAPA group were injected with 5%sodium taurocholate solution,but rats of the RAPA group were injected with rapamycin at 30 min before the injection of 5%sodium taurocholate.All the survival rats in corresponding subgroup were killed at 24 h,36 h,and 48 h after operation respectively,then serum and pancreas tissues of rats were collected,serum inflammatory factors content of IL-0 IL-6,and TNF-a were detected by ELISA method,expression levels of p-mTOR and p-S6K1 in pancreas were detected by Western blot,pancreas tissues were stained by Hematoxylin-Eosin Staining and pathological changes of pancreas were scored under light microscope.Results①At the timepoint of 24 h,36 h,and 48 h,the order of the expression levels of p-mTOR and p-S6Kl in pancreatic tissues of 3 groups were all as follows:SO group<RAPA group<SAP group,there were significant difference among any 2 groups(P<0.05).②IL-ip:at the timepoint of 48 h,the order of the content of IL-lp in 3 groups were as follows:SO group<RAPA group<SAP group,there were significant differences among any 2 groups(P<0.05);IL-6:at the timepoint of 36 h and 48 h,the order of the content of IL-6 in 3 groups were as follows:SO group<RAPA group<SAP group,there were significant differences among any 2 groups(P<0.05);TNF-α:at the timepoint of 48 h,the order of the content of TNF-a in 3 groups was as follows:SO/RAPA group<SAP group(P<0.05),but there was no significant difference between the SO group and RAPA group(P>0.05).③Pancreatic histological score:at the timepoint of 24 h,36 h,and 48 h,the order of the pancreatic histological score in 3 groups was all as follows:SO group<RAPA group<SAP group,there were significant differences among any 2 groups(P<0.05).④The expression levels of p-mTOR and p-S6Kl in pancreatic tissue were positively correlated with the pathological scores of pancreatic tissue(r=0.97,P<0.01;r=0.89,P<0.01).Conclusion Rapamycin can reduce the degree of pancreatic damage in SAP and has protective effect on pancreatic tissue.