OBJECTIVETo investigate the expression of Toll-like receptor 4 (TLR4) in the liver tissue of rats with bile duct ligation (BDL)-induced hepatic fibrosis and evaluate the inhibitory effects of perindopril and losartan on TLR4 expression.

METHODSMale Wistar Rats were randomly divided into sham-operated group (n=6), BDL group, perindopril treatment group (2 mg/kg) and losartan treatment group (50 mg/kg) (n=12). Perindopril and losartan groups were further divided into two subgroups for corresponding treatments by gastric lavage once daily for 14 and 30 days. The protein level of TLR4 in the liver tissue was examined by Western blotting.

RESULTSIn 14-day BDL group, the protein level of TLR4 significantly increased to 6.53∓1.11 folds of that in the sham group (P<0.05), and was lowered significantly to 1.71∓0.41 folds and 0.95∓0.38 folds following perindopril and losartan treatments for 14 days. TLR4 expression significantly increased to 6.51∓0.87 folds and 5.64∓0.87 folds of that of the sham group in perindopril and losartan groups after the 30-day treatments (P<0.05).

CONCLUSIONTLR4 expression is up-regulated in the liver of rats with BDL-induced hepatic fibrosis, and can be lowered by perindopril and losartan treatmemts for 14 days.