Effect of losartan, an angiotensin II antagonist, on secondary biliary cirrhosis

Chronic bile duct obstruction leads to biliary cirrhosis and portal hypertension. The hepatic stellate cells are involved in this process and can be activated by angiotensin II. The aim of the present study was to determine the effect of losartan, an angiotensin II antagonist, on experimental biliary cirrhosis.

Wistar rats were allocated to one of three groups: bile duct ligation (BDL), bile duct ligation and losartan treatment (BDLL), and sham-operated animals (SHAM). After 28 days, liver and spleen weight, hepatic volume, portal flow, and hepatocytes, bile ducts, hepatic stellate cell population and collagen IV volume fraction were evaluated.

The portal flow was lower in the BDL group than in the BDLL group, and lower in both groups than in the SHAM group. Hepatocyte volume fraction was higher in the BDLL group than in the BDL group, and lower in both groups than in the SHAM group. Liver and spleen weight, hepatic volume, hepatic stellate cells population and collagen IV were higher in the BDL group than in the BDLL group, and higher in both groups than in the SHAM group.

These results suggest that losartan can inhibit both the liver fibrosis and portal hypertension occurring in secondary biliary cirrhosis.