The Effects Of The Internal And External Biliary Drainage On The Activites Of Plasma Diamine Oxidase And The Expression Of Defensin-5mRNA In Rats With Obstructive Jaundice

[Objective] To investigate the relationship between the plasma Diamine Oxidase(DAO) activities and the intestinal barrier function, and study the mechanism forbetter drainage of internal biliary drainage(ID) than external biliary drainage(ED)by detecting the level of plasma DAO, the expression of Rat Defensin-5mRNA(RD-5mRNA) and intestinal mucosal morphology in rats with obstructive jaundi-ce (OJ) and after relief from obstruction by ID and ED.[Methods] Sixty adult healthy male SD rats were randomly divided into fourgroups: OJ, ED, ID and shame opetation(SH). There were15rats in each group.SH was produced by separating common bile duct(CBD)locally but not dividing.OJ was induced by CBD ligation and division. ED was performed by exteriorizinga drainage tube at the nape of the rat, while ID was performed by implanting adrainage tube between the dilated end of CBD and duodenum on the8th day afterthe first operation. Blood from inferior vena cava were collected for the test ofDAO activities by the method of ELASA. The terminal ileum was harvested forthe study of routine histology and detecting of the expresstion of RD-5mRNA byRT-PCR.[Results]1.After bile duct ligation, the injures of the intestinal mucosa wereobvious in OJ group with thin mucosa,sparse villous,destruction of the epithelialintegrity and inflammation cell infiltration,and the degree of the intestinalimpairment was2.158±0.579based on the Chiu’s method,while the situations ofthe intestinal mucosa in ED and ID group were recovered,and ID group，whichwas better than ED, was more similar to SH group in intestinal mucosalmorphology. The levels of the DAO in OJ group were increased moredramatically than that in SH, ID and ED groups（8.183±0.211vs3.570±0.280、3.978±0.269、5.051±0.328U/L，p<0.01),and the activities of the DAO in IDgroup,which were similar to the level of SH group(p>0.05),were decreased moresignificantly than that in ED group(p<0.01).The changes of the plasma DAO activities were significantly correlated with the conditions of intestinalmucosa(the correlation=0.89,P<0.01).2.The expression of the RD-5mRNA in OJgroup were decreased more dramatically than that in SH, ID and ED groups（0.0708±0.0061vs0.1895±0.0124、0.1903±0.0143、0.1601±0.0078，P<0.01),and the expression of the RD-5mRNA in ID group,which were similar to thelevel of SH group(p>0.05),were increased more significantly than that in EDgroup (p<0.01).[Conclusion] The level of the plasma DAO can reflect the damage and recoveryof the intestinal barrier function in rats with OJ and after the relief fromobstruction by ID and ED. Compared with ED, ID can increase the expression ofRD-5mRNA more dramatically, decrease infection more effectively, which maybe one of the mechanisms for better drainage of ID than ED.