AIM To investigate effect of losartan,an AT1receptor antagonist,on hepatic fibrosis induced byCCl<sub>;</sub>and to determine whether or not AT1receptors are expressed on hepatic stellate cells,METHODS AND...AIM To investigate effect of losartan,an AT1receptor antagonist,on hepatic fibrosis induced byCCl<sub>;</sub>and to determine whether or not AT1receptors are expressed on hepatic stellate cells,METHODS AND RESULTS Fifty male Sprague-Dawley rats,weighing（180±20）g,wererandomized into five groups（control group,modelgroup,and three losartan treated groups）,inwhich all rats were given the subcutaneousinjection of 40% CCl<sub>4</sub>（every 3 days for 6 weeks）except for rats of control group.Rats of losartan-treated groups were treated with losartan（20 mg/kg,10 mg/kg,5 mg/kg,daily gavage）,After 6weeks liver tissue and serum samples of all ratswere examined.Serum hyaluronic acid（HA）,procollagen typeⅢ（PCⅢ）were detected byradioimmunoassays,van Giesion collagen stainingwas used to evaluate the extracellular matrix of ratswith liver fibrosis.The expression of AT1receptors,transforming growth factor-beta（TGF-β）,and alpha-smooth muscle actin（a-SMA）inliver tissue were determined byimmunohistochemical techniques.Compared withmodel group,serum ALT and AST of losartan-treated groups were significantly reduced（t=4.20,P【0.01 and t=4.57,P【0.01）.Serum HAand PCⅢalso had significant differences（t=3.53,P【0.01 and t=2.20,P【0.05）.Thedegree of fibrosis was improved by losartan and correlated with the expressions of AT1 receptors,TGF-β,and α-SMA in liver tissue.CONCLUSION AT1 receptor antagonist,losartan,could limit the progression of the hepatic fibrosisinduced by CCl<sub>4</sub>.The mechanism may be related tothe decrease in the expression of AT1 receptorsand TGF-β,ameliorating the injury of hepatocytes;activation of local renin-angiotensin system mightrelate to hepatic fibrosis;and during progressionof fibrosis,activated hepatic stellate cells mightexpress AT1 receptors.展开更多
文摘AIM To investigate effect of losartan,an AT1receptor antagonist,on hepatic fibrosis induced byCCl<sub>;</sub>and to determine whether or not AT1receptors are expressed on hepatic stellate cells,METHODS AND RESULTS Fifty male Sprague-Dawley rats,weighing（180±20）g,wererandomized into five groups（control group,modelgroup,and three losartan treated groups）,inwhich all rats were given the subcutaneousinjection of 40% CCl<sub>4</sub>（every 3 days for 6 weeks）except for rats of control group.Rats of losartan-treated groups were treated with losartan（20 mg/kg,10 mg/kg,5 mg/kg,daily gavage）,After 6weeks liver tissue and serum samples of all ratswere examined.Serum hyaluronic acid（HA）,procollagen typeⅢ（PCⅢ）were detected byradioimmunoassays,van Giesion collagen stainingwas used to evaluate the extracellular matrix of ratswith liver fibrosis.The expression of AT1receptors,transforming growth factor-beta（TGF-β）,and alpha-smooth muscle actin（a-SMA）inliver tissue were determined byimmunohistochemical techniques.Compared withmodel group,serum ALT and AST of losartan-treated groups were significantly reduced（t=4.20,P【0.01 and t=4.57,P【0.01）.Serum HAand PCⅢalso had significant differences（t=3.53,P【0.01 and t=2.20,P【0.05）.Thedegree of fibrosis was improved by losartan and correlated with the expressions of AT1 receptors,TGF-β,and α-SMA in liver tissue.CONCLUSION AT1 receptor antagonist,losartan,could limit the progression of the hepatic fibrosisinduced by CCl<sub>4</sub>.The mechanism may be related tothe decrease in the expression of AT1 receptorsand TGF-β,ameliorating the injury of hepatocytes;activation of local renin-angiotensin system mightrelate to hepatic fibrosis;and during progressionof fibrosis,activated hepatic stellate cells mightexpress AT1 receptors.
