Study On The Mechanism Of Exogenousbile Acid In The Recovery Of Liver Regeneration Caused By External Biliary Drainage

Objective: To investigate the possible mechanism of exogenous bile acids(CA)in the recovery of liver regeneration caused by biliary drainage.Methods: 90 healthy male SD rats were randomly divided into 3 groups,which were non drainage group(n=30),external drainage group(ED group,n=30)and external drainage group fed with 0.2% exogenous bile acid group(ED + 0.2% CA group,n=30).Undergoing a 70% liver resection after treatment for 7 days and the rats were killed at 0 h,4 h,12 h,24 h,48 h and 72 h respectively after surgery.Collect the serum of rats at different checkpoint and examined the(Aspartate aminotransferase,aspartate aminotransferase,alanine aminotransferase(AST),Alanine aminotransferase,ALT),albumin(Albumin,ALB),respectively.Liver tissue was collected after resection and liver regeneration rate at each time point of different groups were detected.The expression of proliferating cell nuclear antigen(Ki-67)in liver tissue at each time point was also detected by immunohistochemistry.Ileal tissue was collected to detect the protein and mRNA expression of fibroblast growth factor 15(FGF15)in each groups.Results: After hepatectomy,ED group and ED + 0.2% CA group and non drainage group,the levels of ALT and AST in serum of ED group were significantly increased;ED + 0.2% CA group compared with the non drainage group,AST and ALT in serum were significantly increased;in addition,compared with the ED + 0.2% CA group,the ALB level of ED group in serum were significantly reduced;ED + 0.2% CA group compared with the non drainage group,the serum ALB levels were significantly reduced,the differences were statistically significant(P < 0.05).The expression level of FGF15 protein and mRNA in ED group in each period after partial hepatectomy were significantly lower than that of ED + 0.2% CA group and non drainage group(P < 0.05),the overall expression showed a downward trend after rising,and reached the peak at 24 h,which were significantly lower than ED + 0.2% CA group and non drainage group(P < 0.05),while the expression of ED + 0.2% CA group of FGF15 protein and mRNA in each period and also the peak value was significantly lower than that of non drainage group(P < 0.05).After liver resection,ED group compared with ED + 0.2% CA group and non drainage group,the rate of liver regeneration and liver tissue of proliferating cell nuclear antigen(Ki-67)expression levels were significantly lower in 48 h and 72 h period,the difference was statistically significant(P < 0.05);and ED + 0.2% CA group and non drainage group compared to the rate of liver regeneration and liver tissue of proliferating cell nuclear antigen(Ki-67)levels were significantly lower in the 48 h period,the differences between groups were statistically significant(P < 0.05).Conclusion: Exogenous CA supplement could upregulate the expression of intestinal FGF15,which could facilitate the liver regeneration,to partially improve the delay of liver regeneration which induced by biliary drainage.