Abstract: Objective To investigate the effects of pancreatic kininogenase on pressure,myocardical fibrosis and serum nitric oxide (NO) level in spontaneously hypertensive rats (SHR). Methods Twenty-four (fifteen weeks) male SHR were randomly divided into three groups:SHR group,pancreatic kininogenase group and captopril group（n=8 ），8 male Wistar kyoto rats with normal blood pressure were considered as control group. Pancreatic kininogenase was given by peritoneal injection (7.2 U•kg^-1•d^-1), captopril was given by intragast ric administration（10 mg•kg^-1•d^-1）, the rats in SHR group and rats with normol blood pressure in control group were treated with 0.9% NaCl（2 mL•kg^-1•d^-1）administered through peritoneal injection. After four-week experiment, the pressure was measured in rats througth carotid artery,then the rats were sacrificed , and LVMI,CVF,PVCA and serum NO level were measured. Results In SHR group, SBP,LVMI,CVF and PVCA were higher, serum NO level was decreased obviously than those in control group (P<0.05). After treatment of pancreatic kininogenase,the serum NO level raised obviously,other indexes obviously reduced than those in SHR group (P<0.05),but except SBP,there were no significant difference compared with captopril group (P>0.05). Conclusion Pancreatic kininogenase can obviously reduce the blood pressure and reverse myocardial fibrosis,its mechanism may be concerned with the increasing of NO level in SHR.

Key words: therapeutical use, nitric oxide, endomyocardial fibrosis, rats, inbred SHR