Abstract: AIM To investigate the changes of fasting circulating plasma vasostatin (VS)-2 levels and their relationship with blood pressure in spontaneously hypertensive rats (SHR). METHODSFasting plasma total VS-2 levels were measured by ELISA in 14 SHR and 14 Wistar-Kyoto (WKY) rats. Blood pressure, heart rate (HR) and baroreflex sensitivities (BRS) were measured by continuous recording system used for conscious freely moving rats. RESULTSVS-2 levels were significantly higher in SHR group compared with those in WKY group ［(0.43±0.05) pg/ml vs.(0.34±0.05) pg/ml, P<0.01］. Systolic blood pressure (SBP), diastolic blood pressure (DBP) and mean blood pressure (MAP) were positively correlated with VS-2 levels (r=0.781, P<0.05; r=0.822, P<0.05; r=0.918, P<0.01). HR was not correlated with VS-2 levels (r=0.350, P>0.05). BRS was negatively correlated with VS-2 levels (r=-0.959, P<0.01). In a multiple regression model including SBP, DBP, MAP and BRS, MAP and BRS were independent variables of VS-2 levels (standardized coefficient=-0.021, P<0.05; standardized coefficient=0.195, P<0.05; respectively). CONCLUSIONFasting circulating plasma VS-2 levels in SHR are higher than those in WKY rats, suggesting VS-2 may play a role in the regulations of hypertension.