Effects Of Different Biliary Drainage Methods On Intestinal Mucosal Mechanical Barrier Function In Rats With Obstructive Jaundice

ObjectiveIn this experiment,the rats were used to establish OJ models. This models were executed different biliary drainage methods-internal biliary drainage and external biliary drainage. At the end of the experiment,we discussed the effects of different biliary drainage methods on intestinal mucosal mechanical barrier function in rats with OJ by observed the histomorphological changes in intestinal mucosa in rats of each group,determined the serum endotoxin level and protein expression of PCNA and Caspase-3in the cells and tight junction-related protein—occludin and ZO-1in the tissues of intestinal mucosa. Accordingly,we could provide some theoretical basis for the patients who suffering OJ to choose what kind of biliary drainage methods.MethodsSixty SD rats were used to establish OJ models by common bile duct ligation. One week after operation, the rats were equally randomized into non-drainage group (underwent no biliary drainage), internal drainage group (underwent internal biliary drainage) and external drainage group (underwent external biliary drainage), and the drainage time was one week. Twenty SD undergoing sham operation served as control group and the total experiment time was two weeks. At the end of the experiment, the serum endotoxin level and protein expression of PCNA and Caspase-3in the cells and occludin and ZO-1in the tissues of intestinal mucosa of each group were determined by ELISA assay and IHC assay and Western blot analysis respectively, and the histomorphological changes in intestinal mucosa were also observed.Results1Changes of the serum endotoxin level:The serum endotoxin levels in OJ rats of non-drainage group and external drainage group were increased markedly, and their differences versus control group reached statistical significance (both P<0.01),but no significant difference was observed between the two drainage groups (P>0.05); the serum endotoxin level of internal drainage group was significantly lower than that of non-drainage group or external drainage group (both P<0.01), and showed no significant difference versus control group (P>0.05).2The protein expression of PCNA in the cells of intestinal mucosa:The protein expression of PCNA in the cells of intestinal mucosa in OJ rats of non-drainage group and internal drainage group and external drainage group were decreased markedly, and their differences versus control group reached statistical significance (both P<0.01);but internal drainage group and external drainage group were increased markedly, and their differences versus control group reached statistical significance (both P<0.01).Internal drainage group were increased markedly,and it differences external drainage group reached statistical significance (P<0.01).3The protein expression of Caspase-3in the cells of intestinal mucosa:The protein expression of Caspase-3in the cells of intestinal mucosa in OJ rats of non-drainage group and internal drainage group and external drainage group were increased markedly, and their differences versus control group reached statistical significance (both P<0.01);but internal drainage group and external drainage group were decreased markedly, and their differences versus control group reached statistical significance (both P<0.01).Internal drainage group were decreased markedly,and it differences external drainage group reached statistical significance (P<0.01).4The protein expression of tight junction-related protein—occludin and ZO-1in the tissues of intestinal mucosa:Compared with control group, the protein expressions of tight junction-related protein—occludin and ZO-1in intestinal mucosa in rats of non-drainage group and external drainage group were significantly decreased (all P<0.01), and the degree of decrease in external group was more evident than that in non-drainage group (both P<0.01); the expression levels of the two proteins in internal drainage group were significantly higher than those in non-drainage group or external drainage group (all P<0.01), and were similar to those in control group (both P>0.05).5The representation of intestinal mucosa by light microscope:the intestinal mucosal integrity was damaged in OJ rats of both non-drainage group and external group with large or moderate amounts of inflammatory cell infiltration, while the intestinal mucosal integrity was maintained intact with less inflammation in OJ rats of internal drainage group.ConclusionInternal biliary drainage has protective effect on the intestinal mucosal barrier in OJ rats, and the mechanism is probably due to the maintaining effect of bile on the cells of intestinal mucosa and tight junction-related protein expression in intestinal epithelial cells.