【作者】 杨书英；

【导师】 曹书华；

【作者基本信息】 天津医科大学 ， 急诊医学， 2008， 硕士

【摘要】 目的:通过火闭肠系膜上动脉(superior mesenteric artery,SMA),建立大鼠小肠缺血再灌注(ischemia reperfusion,I/R)损伤模型,观察不同时限小肠组织形态学变化、肠道通透性改变、氧自由基损伤和肠粘膜细胞凋亡情况,以及凉膈散对上述相关指标的影响,旨在观察凉膈散对I/R损伤肠道的保护作用,并探讨其可能的作用机制,为临床新用途提供理论依据。方法:选用健康雄性Wistar大鼠168只,随机分为5组,分别为正常组(不予任何处理)、假手术组(只分离而不夹闭SMA+术后生理盐水每日灌胃一次)、模型组(肠I/R损伤模型制备+术后生理盐水每日灌胃一次)、凉膈散治疗组(肠I/R损伤模型制备+术后凉膈散每日灌胃一次)、凉膈散防治组(术前连续5天每日凉膈散灌胃一次+肠I/R损伤模型制备+术后凉膈散每日灌胃一次)。除正常组所有时点共用8只大鼠外,其余每组根据SMA缺血45min后再灌注3h、12h、24h、48h、72h又分为5个小组,每小组8只大鼠。分别测定各组动物的小肠粘膜病理损伤Chiu氏评分、门静脉血浆D-乳酸值、小肠组织匀浆MDA含量和SOD活力、肠粘膜细胞凋亡指数、Bcl-2和Bax的表达情况。应用SPSS11.5统计软件进行统计分析处理。结果:1.模型组动物肠粘膜结构破坏严重,Chiu氏评分、血浆D-乳酸值明显高于正常组、假手术组动物(p＜0.05或p＜0.01),且均于再灌注24h时达高峰。经凉膈散干预后,Chiu氏评分、血浆D-乳酸值较模型组下降。2.与正常组、假手术组动物相比,模型组动物小肠匀浆MDA含量明显增高(p＜0.05或p＜0.01),于再灌注24h达高峰;SOD活力明显下降(p＜0.05或p＜0.01),于再灌注24h至最低水平。与模型组相比,凉膈散治疗组和防治组MDA含量降低,SOD活力升高。3.模型组动物于再灌注3h,肠粘膜细胞凋亡指数、Bcl-2和Bax的表达均明显高于正常组、假手术组动物(p＜0.05或p＜0.01)。随后Bcl-2的表达下降,而凋亡指数、Bax的表达继续升高,于再灌注24h后,Bcl-2的表达开始回升,凋亡指数和Bax的表达逐渐降低。与模型组相比,凉膈散治疗组和预防组凋亡指数下降,Bcl-2的表达增强,Bax的表达减弱。4.各指标凉膈散治疗组和防治组相比,以防治组效果更为显著(p＜0.05或p＜0.01)。结论:1.肠缺血再灌注后肠粘膜形态严重受损,肠粘膜通透性增高,肠道屏障功能破坏。2.肠缺血再灌注损伤可以引起机体内OFR生成增多,脂质过氧化反应增强,组织抗氧化能力下降:抑凋亡基因Bcl-2表达减弱,促凋亡基因Bax表达增强,小肠粘膜细胞凋亡增多。3.凉膈散可以明显减轻肠缺血再灌注大鼠小肠粘膜的损伤程度,降低肠粘膜通透性,改善肠道屏障功能,对肠道具有保护作用。4.凉膈散对肠缺血再灌注损伤大鼠肠道的保护作用机制,可能与其减少机体内OFR的生成,降低脂质过氧化反应的程度,提高组织的抗氧化能力;上调抑凋亡基因Bcl-2的表达,下调促凋亡基因Bax的表达,抑制小肠粘膜细胞凋亡有关。更多还原

【Abstract】 Objective:An intestinal ischemic reperfusion(I/R)rat model was adopted by blocking the SMA to observe the change of intestinal morphology and permeability,the condition of oxygen free radical damage and apoptosis of intestinal mucosa,then the influence of Liangge San on above-mentioned correlated index.The aim of this study was to evaluat the protective effect of Liangge San on intestinal I/R injury,and its possible mechanisms,in order to provide pharmacological evidence for its new clinical use.Method:A total of 168 male Wistar rats were randomly divided into 5 groups as follows:normal group(without any management),sham operation group(SMA was only isolated without clamping+saline was given once a day after operation),model group(SMA was isolated and clamped+saline was given once a day after operation),Liangge San therapeutics group(SMA was isolated and clamped+Liangge San was given once a day after operation),Liangge San prevention and cure group(Liangge San was given once a day for five days before operation+SMA was isolated and clamped+Liangge San was given once a day after operation).Besides 8 rats were chosen randomizedly as normal group,the other groups divided into 5 groups again according to rats in each group were killed at 3,12,24,48,72 hours after I/R(each n=8).At different time point,Chiu’s score,D- lactic acid content ofjanitrix blood plasma,MDA content and SOD activity of intestinal homogenate,apoptotic index,the expression of the apoptotic gene Bcl-2 and Bax in the small intestine cells were measured in all rats of each group.Carried on statistical analysis processing using the SPSS 11.5 statistics software.Resuilts:1.After I/R,the instenal morphology was significantly injuried,Chiu’s score and D-lactic acid content of blood plasma in model group were higher than that in other groups(p＜0.05 or p＜0.01),all of them reached the peak at 24 hour.Chiu’s score and D-lactic acid content in Liangge San intervention groups were lower than those in model group.2.Compared with normal group and sham operation group,the intestinal MDA content of model group increased after ischemia(p＜0.05 or p＜0.01),it reached the peak at 24 hour after reperfusion,then it decreased gradually;SOD activity of model group decreased and reached the lowest point at 24 hour after ischemia reperfusion(p＜0.05 or p＜0.01).Compared with model group,Liangge San therapeutics group,prevention and cure group could decrease MDA content and upgrade SOD activity significantly.3.The apoptotic index,the expression of Bcl-2 gene and Bax gene in intestinal mucosal cells of rats of model group were obviously higher than that in normal group and sham operation group at 3 hours after I/R(p＜0.05 or p＜0.01).Then the expression of Bcl-2 degraded,the apoptotic index and the expression of Bax upgraded continuely.Afler 24 hours,the expression of Bcl-2 began to rise,the apoptotic index and the expression of Bax began to lower.Compared with model group,the expression of Bcl-2 gene enhanced,the apoptotic index and the expression of Bax gene degraded in Liangge San intervention groups.4.Compared with Liangge San therapeutics group in all the index,the effect of Liangge San prevention and cure group was more remarkable(p＜0.05 or p＜0.01)Conclusion:1.The intestinal I/R injury can destroy the mucosa structure of small intestine,increase the intestinal permeability,destroy the function of intestinal barrier.2.The intestinal I/R in rat could induce the production of oxygen free radical increase, the degree of lipid peroxidation enhancement,the activity of antioxidase attenuation, the expression of Bcl-2 gene increase,the expression of Bax gene decrease,the apoptosis of iniestinal mucosa cells increase notably.3.Administration of Liangge San could alleviate the small intestinal histopathologic damage,decrease the intestinal permeability,ameliorate the function of intestinal barrie,and provide protective effect on intestinal I/R injury in rats.4.Liangge San could protect the intestinal tract injury from the intestinal I/R in rats was possibly dued to clean the oxygen free radical,reduce the degree of lipid peroxidation,improve the activities of antioxidase,inhibit the apoptosis of iniestinal mucosa cells during I/R by up-regulating the expression of Bcl-2 gene and down-regulating the expression of Bax gene.更多还原