The Effects Of Internal And External Biliary Drainage On The Intestinal Mucosal Dysfunction In Rats With Obstructive Jaundice

[Backgrounds] Obstructive jaundice (OJ) is associated with a high postoperative complications and mortality. Internal biliary drainage (ID) can recover enterohepatic circulation of bile acids, and reduce endotoxin-related complications and infection rate more obviously than external biliary drainage (ED). The mechanism that ID is superior to ED in relief of OJ remains unclear. Our previous studies demonstrates that the ID is superior to the ED in terms of reversing Kupffer cell dysfunction in rats with OJ. We assume that the mechanism were related to the intestinal dysfunction, which was induced by bile acid as a signaling molecule. Farnesoid X receptor (FXR) may play an important role in the intestinal dysfunction.[Aims] The aim of the present study was to investigate the mechanism by measurement of intestinal mucosal morphology, occludin, total bile acid, FXR and bacterial translocation rate with OJ andrelief of obstruction by ID and ED. [Methods] Male adult Sprague-Dawley rats were randomly assigned to four groups:sham operation (SH, n=14),obstructive jaundice (OJ, n=14), external drainage (ED, n=15) and internal biliary drainage (ID, n=16). Rat models were successfully established by twice operations. OJ was induced by common bile duct (CBD) ligation and division. SH was produced by separating CBD locally but not dividing. ED was performed by exteriorizing a drainage tube at the nape of the rat, while ID was performed by implanting a drainage tube between the dilated end of CBD and duodenum on the 8th day after the first operation. Blood from portal vein and inferior vena cava were collected for bacterial culture. Level of serum total bile acid(TBA) and white blood cell count (WBC) were tested. The terminal ileum was harvested for study of routen histology. Occludin and FXR were determined by immunohistochemical method.[Results] After bile duct ligation, WBC and TBA were significantly increased (11.4±2.7x109/L and 118.9±39.0μmol/L respectively)compared with that in SH rats(5.5±1.0×109/Land 38.0±15.0μmol/L respectively, bothP<0.05). The ileum villous became the lowest. The mucosal lesion grade according to Chiu was high. The expression of FXR was decreased while occludin decreased. The BTR was 57.1%, but increased to 80% in ED and 62.5% in ID. After ED, WBC reduced lightly while TBA reduced greatly. The ileum villous became higher and thinner, and the mucosal lesion grade was lower than OJ. The expression of FXR was the weakest but the occludin did not change. After ID, not only WBC was decreased,but also TBA, ileum structure, mucosal lesion grade, expression of FXR and occludin were almost as same as that in SH(P>0.05). The bacterial species and BTRs were the same in the portal vein and inferior vena cava in each group.[Conclusion] Compared with ED, ID can recover the enterohepatic circulation, increase expression of FXR, repair structure of intestinal and decrease infection more effectively.