To investigate the
antihypertensive effects of polypeptides prepared from Acetes chinensis on ren- ovascular hypertensive
rats (RHR) and related mechanisms, polypeptides were prepared from Acetes chinensis with alkaline and neutral proteases, and the effects of these two polypeptides on the activity of ACE were measured by Cushman-Cheung assay in vitro. RHR models were made with two-kidney one clip assay, and
antihypertensive effects were studied in RHR pretreated with polypeptides for long course or by acute venous injection. Arterial blood pressure, respiration and plasma angiorensin Ⅱ(Ang Ⅱ) were measured respectively. The twopolypeptides markedly inhibited the activity of ACE in vitro with IC50 of AP (15.61mg/L) and NP (16.95 mg/L). They remarkably reduced the arterial blood pressure in the two cases referred above. Plasma Ang Ⅱ of RHR greatly decreased after pretreated with the polypeptides. Respiration of RHR had the same variation trend as blood pressure. Moreover, AP showed stronger antihypertensive and Ang Ⅱ -reducing effects than that of NP. The effects of 200 μ g/g AP were similar to that of 14 μg/g captopril. Polypeptides from Acetes chinensis showed strong antihypertensive effects in RHR. One possible mechanisms underlying the antihypertensive effects may be associated with its actions on decreasing the production of Ang Ⅱ.