玉米降血压肽对体内外血管紧张素转化酶活性的抑制作用

目的研究玉米降血压肽在体内外对血管紧张素转化酶(ACE)的活性抑制作用及机制,为探讨降血压肽的降压机制提供实验依据。方法用反相高效液相色谱法测定玉米降血压肽在体外对ACE的抑制动力学,同时测定多次给药12周后SHR大鼠体内不同组织的ACE活性和血浆AngⅡ浓度。结果玉米降血压肽竞争性抑制ACE活性,IC50为15.0μmol/L,玉米降血压肽能显著降低血清、主动脉和肺ACE活性(P<0.01),而对心、脑、肾的ACE活性抑制作用不显著(P>0.05),同时玉米降血压肽能显著降低血浆中血浆AngⅡ浓度(P<0.01)。结论玉米降血压肽对体内外ACE都有竞争性抑制作用,但在体内不同部位其抑制效果不同,同时其降压作用是通过抑制ACE活性、降低AngⅡ浓度来实现的。

Effect of corn antihypertensive peptide on ACE activity in vivo and in vitro

Purpose To investigate the inhibitory effect and the mechanism of corn antihypertensive peptide on ACE activity in vivo and in vitro.Methods The inhibitory dynamics of corn antihypertensive peptide to ACE and the activities of ACE in different tissues of SHR administrated with the corn antihypertensive peptide for 12 weeks were determined by RP-HPLC.Results The inhibitory dynamics of corn antihypertensive peptide to ACE was competitive inhibition with IC50 of 15.0 μmol/L,and the peptide could reduce the activities of ACE in serum, artery and lung significantly(P<0.01),but there are no significant effects on the activities of ACE in heart,brain and kidney(P>0.05).The peptide also could reduce plasma AngⅡlevel(P<0.01).Conclusion Corn antihypertensive peptide may reduce SBP through inhibiting the activities and reducing the AngⅡlevel,but the inhibitory effect was different in different tissues.