Objective To investigate whether adiponectin (AD) has any impact on the hemodynamics of rat portal hypertension model and the action mechanism.Methods Thirty male SD rats were assigned into 3 groups:sham,bile duct ligation (BDL) with AD,BDL with normal saline (NS).The hemodynamic changes after intravenous administration of AD were observed.The liver microcirculation was examined under the in vivo microscopy.The effects of AD on hepatic stellate cell contraction were assessed by using collagen gel contraction assay.Results AD acutely reduced portal pressure by 9.7% (P < 0.05),and portal vein blood flow by 13.5% (P <0.05) in BDL rats without affecting mean arterial pressure and heart rate.The hepatic sinusoid diameter was markedly dilated by 35.7% (P < 0.01) after AD administration.AD diminished endothelin(ET)-1-elicited HSC contraction,while the nitric oxide (NO) inhibitor L-nitro arginine methyl ester (L-NAME) could reverse this effect.Conclusion AD can acutely decrease portal pressure without deteriorating systemic hemodynamics in rat cirrhotic model,which may be contributed to the fact that AD diminishes hepatic stellate cell contraction and dilates the hepatic sinusoid. Key words: Liver cirrhosis; Portal hypertension; Adiponectin; Hemodynamics