Establishment Of Obstructive Jaundice And External-internal Biliary Drainage Mice Model And Bile Acid Receptor TGR5 Expression In Liver Tissue

Background:Jaundice is one of the most common physical signs which caused by the increased bilirubin in the blood for different reasons. When obstructive jaundice (OJ) occurred, it can lead to immune status changes, intestinal immune dysfunction, severe malnutrition, coagulation abnormalities, impaired renal function, heart failure, liver damage and other organ damage. It is also controversial whether should relieve the jaundice before operation and its methods. Meanwhile, researches showed the regulatory function of TGR5 in the liver inflammatory reaction process. Therefore, the present study was designed to explore the mice model of obstructive jaundice, external biliary drainage and internal biliary drainage based on the rat model. We conducted a preliminary study of the TGR5 expression for mice liver with OJ and after external and internal bile drainage, exploring whether TGR5 regulated this pathophysiology progress.Materials and Methods:To establish mice model,153 male Kunming mice were randomly divided into sham operation group (SH), obstructive jaundice group (OJ), external bile drainage group (ED), and internal bile drainage group (ID). After establishing the SH group and OJ group in the first operation, the second operation was performed 5 day later by using rats model as reference when obstructive jaundice occurred. To confirm the mice model and observe the change of liver tissue, blood sample and liver tissue were gathered 5 days after the first operation for SH and OJ group, and 5 days after the second operation for ID and ED group. The biochemical criterion of blood sample was detected by the clinical laboratory. And the change of liver tissue was detected by HE staining. To explore whether TGR5 was involved in regulation of liver inflammation, the expression of TGR5 in liver tissue was detected by real time-PCR and western blot.Results:The present study successfully established the animal model of obstructive jaundice, external bile drainage and internal bile drainage. The HE staining of liver tissue and detection of blood sample suggested that there was no obvious abnormal for SH group but for OJ group with fibrosis, edema and inflammatory necrosis of liver lesion and increasing bilirubin. After ED and ID treatment, the liver injury and biochemical indexes was improved in different degree, both of which showed that obstructive jaundice and its drainage model was reliable and effective. The result of real-time PCR showed that mRNA expression of TGR5 was increased 1.3 times in OJ group compared with SH group (P=0.005) and was reduced significantly in ED and ID group (P<0.05) which has no significant difference between SH group. However, there has no obvious effect on the expression of TGR5 mRNA for different drainage methods. The level of protein was similar with mRNA which suggested that the TGR5 protein of obstructive jaundice group was improved remarkably compared with SH group and was gradually back to normal after the drainage. The effect on TGR5 expression of external drainage and internal drainage method was no difference.Conclusion:The present study successfully established the mice model of obstructive jaundice, external bile drainage and internal bile drainage. The TGR5 expression of liver tissue was increased for mice in OJ group which can be reversed by procedure to relieve jaundice. The TGR5 expression maybe associated with the liver injury after the occurrence of obstructive jaundice, and may reduce the inflammation of liver tissue after bile drainage.