Viability and plasma vitamin K levels in the common bile duct-ligated rats

The common bile duct-ligated (CBDL) rat, which is widely used as a model of human cirrhosis, rapidly develops secondary biliary cirrhosis (SBC) within 4 weeks. The CBDL rat shows poor viability, however, a detailed examination of the causes of its death has not been made. In this study, we investigated the outcome of bile duct ligation in detail and attempted to extend the life span of this model by feeding the animals a diet supplemented with nutrients. Survival rate, blood chemistry, blood cell counts, plasma levels of K vitamins and liver histology were compared among CBDL rats fed a standard diet and an enriched diet. Sham-operated rats were used as a control. Six out of 18 CBDL rats fed the standard diet died within 32 days of operation. The cause of death was massive internal hemorrhage in various organs or body cavities. All CBDL rats fed the enriched diet survived more than 31 days, but the viability of CBDL rats was not significant between those fed the standard diet and the enriched diet. The degree of anemia correlated significantly with the prolongation of prothrombin time. Plasma vitamin K1 levels in CBDL rats were significantly lower than those in sham-operated rats, but vitamin K2 levels were similar. We suggest that massive hemorrhage, which was the direct cause of death, is caused by the impairment of hemostasis resulting from vitamin K deficiency. The enriched diet with vitamin K nutritional supplements seemed to contribute to the prolongation of the life span of CBDL rats.