Ang (1–7) is a modulator of the vasoconstrictor actions of Ang I and Ang II

摘要

Introduction: The role of angiotensin (Ang) (1–7) on the vasoconstrictor effect induced by angiotensins could be different in the presence of an ACE inhibitor or an ARB because Ang II is formed through several pathways. Therefore, the role of Ang (1–7) in Ang I and Ang II contraction was evaluated in aortas from Wistar rats after 48-hour coronary occlusion treated with captopril or losartan. Methods: Concentration-response curves to Ang I or Ang II were conducted in the absence or presence of Ang (1–7) and A779: a) sham group; b) 48-hour coronary occlusion; c) treated with captopril or d) losartan (3.1 mg/kg, i.m.). Results: Captopril caused a significant increase in the contractile effect of Ang I and Ang II, while losartan reduced it. The presence of Ang (1–7) in the captopril group showed a reduction of the contraction compared to the sham group, while the treatment with losartan did not show a significant difference. Ang (1–7) presents effects different from Ang I or Ang II. Conclusion: Ang (1–7) showed a modulatory role, suggesting Ang I did as well after treatment with an ACE inhibitor but not with an AT1 receptor antagonist.