Effects of External Biliary Drainage in Regenerating Capacity of Rat Liver

Abstract

We undertook this study to evaluate the effects of obstructive jaundice and external biliary drainage on regenerating capacity after partial hepatectomy. Male Sprague-Dawley rats aged 10 to 12 weeks were used. Each animal was lightly anesthetized with ether. Using cut-down technique, a polyethylene tube of an outer diameter of 0.965mm was inserted into the proximal common bile duct and fixed in place. Then two groups of rats were made; Group-I with only simple external drainage group and Group 11 with jaundice. In group 11, rats were jaunduced by ligating the external end of the tube from extrahepatic bile ducts for 5 days and then the jaundice was reliered. Seventy percent hepatectomy was carried out using the method of Higgins-Anderson at 1, 3, and 5 days after biliary decompression in Group I, and at 0, 1, 3 and 5 days after biliary decompression in Group II. Both resected livers from the partial hepatectomy and the remnant livers regenerated for 24 hours were stored at -70°C. From the collected liver specimens, the degree of regeneration was measured by the proliferative index using flow cytometry. The results was the following; 1. The regeneration capacity of the hepatectomized liver in Group I was decreased in proportion to the time elapsed. 2. An obstructive jaundice itself markedly increased the regenerating capacity of the liver. 3. The regenerating capacity of hepatectomized liver was not inhibited by the obstructive jaundice. 4. The external biliary drainage suppressed regenerating capacity of the liver at the early stage of obstructive jaundice. In conclusion, the regenerating capacity of partially hepatectomized liver was not inhibited by early obstructive jaundice, And was significantly suppressed by external biliary drainage. It is suggested that the loss of bile is a serious negative effect on liver cell proliferation.