Causes of natural regression of obstructive jaundice in rats and time for surgery to reduce yellowing

Objective to investigate the causes of spontaneous resolution of obstructive jaundice in rats, and to provide theoretical basis for rational selection of experimental model and duration of yellow reduction surgery. Methods 54 rats were randomly divided into the bile duct ligation and dissociation group (group A), the bile duct ligation group (group B) and the control group (group C), with 18 rats in each group. Serum total bilirubin (TBIL) and alanine aminotransferase (ALT) were detected on the first, 3, 7, 14 and 21 d after the operation, cholangiography was performed on the 21d with meglumine diatrizoate, and bile duct radionuclide imaging was performed on the 28 d. One-way anova was used to compare the laboratory results between groups and within groups. Results TBIL increased in group 1dA and group B, and peaked on day 7. On the 14th day after the operation, the icterus began to be separated from the two groups, 3 (16.7%) rats in group A and 14 (77.8%) rats in group B began to decline, and the comparison between groups A and B [ (136.5±14.3) mumol/L ratio (78.5±12.8) mumol/L, t=196.203, P<0.05]. After the operation, those in group 21dA and group B basically returned to normal level, and ALT showed the same rule (t=57.450, P<0.05). 21 d after the operation, cholangiography was performed with meglumine diatrizoate. The bile ducts above the ligation line were significantly dilated in group A, and the contrast agent did not spread to other sites. In group B, the proximal bile duct was slightly dilated, and contrast agent was observed to enter the intestinal cavity through the adhesion omentum duct at the hilum of liver. Radionuclide imaging and quantification of the proximal dilated bile duct 28 days after the operation, no radionuclide was discharged into the intestinal tract in the rats in group A, while the radionuclide was discharged into the intestinal tract from the liver through the attached omentum at the hilar of the liver in the rats in group B after 5min, and the radionuclide was developed. Conclusion the spontaneous resolution of obstructive jaundice in rats may be caused by the presence of small bile duct or adhesive retinal duct shunt in the hepatic hilum. Bile duct rupture should be the first choice for biliary obstruction model, and yellow reduction intervention can be conducted after modeling for 14 d. Key words: Rats; Spontaneous resolution of jaundice; Reason; Surgery reduces yellow time