Animal model for biliary cirrbosis has been obtained by ligating the common bile duct of Wistar rats.The pathologic and ultrapathologic changes of liver were studied in rats whose common bile duct had been irrevesibly ligated for 1～86 days by light and electron microscopy.The pathogenesis of liver fibrosis and nodular formation of experimental biliary cir rhosis was disussed.Cholestasis after the ligation of common bile duct led to the damage of hepatocytes,necrosis and stimulating the proliferation of ductuloid epithelial cells,the latter undergone differentiation and transformation,and most of them formed bile ductules and a few of them formed nodules of hepatocytes.The ductuloid and ductular epithelial cells have the ability for synthesizing collagens.The liver lobules were surrounded and separated by connective tissue septa which were cqmposed of proliferated bile ductules,fibroblasts,phagocytes, blood capilarys and proliferaled collagen fibers,and then pseudolobules were formed.Finally, the liver cirrhosis developped.
