Difference of regulation of angiotensin1-7 and achtylcholine on relaxation of rats aorta

Objective To explore the relaxation effect of angiotensin1-7(Ang1-7)or acetylcholine(Ach)on rats aorta contraction,which were induced by angiotensin Ⅱor phenyladrenalin.Methods Aorta of rats were placed in constant temperature[(37±0.5) ℃]filling device,and the relaxation reaction induced by Ang1-7 or Ach was recorded by physiological recorder.Results The inhibition effect of Ach on the aorta contaction induced by phenyladrenalin was stronger than Ang1-7(P0.05),their half concentrations of inhibition(IC50)were[(175±36)×10-9] mol·L-1 and[(227±14)×10-9] mol·L-1.The inhibition effect of Ang1-7 on the aorta contraction induced by anyiotensin Ⅱ was stronger than Ach(P0.05),and their IC50 were[(157±8)×10-9] mol·L-1and [(273±12)×10-9] mol·L-1 respectively.Conclusion The relaxation effect of Ang1-7 on rats aorta contraction induced by angiotensin Ⅱ was stronger,but weaker when the contraction was induced by phenyladrenalin,than acetylcholine.