[Interactions between angiotensin-(1-7)and angiotensin II in isolated rat portal vein].
Our preliminary data show for the first time the interaction between angiotensin-(1-7) (Ang-(1-7)) and angiotensin II (Ang II, 10 nM) in isolated rat portal vein. Very low concentrations (10 nM) of Ang-(1-7) have marked functional antagonizing effects on Ang II-induced contractions. High concentrations of Ang-(1-7) (1-10 mM) do not affect the effects of Ang II. The effects of low concentration Ang-(1-7) might be associated to the interaction with Ang-(1-7) specific receptors and the own contractile effects (approximatively 28%) at high concentrations might be assign to the interaction with angiotensin specific receptors AT1. But, the lack of effects of Ang-(1-7) high concentrations on Ang II-induced contractions hardly might be associated to the interaction with AT1 receptors. Although losartan was entirely blocking the Ang-(1-7) effects, there is in the literature a series of data showing that Ang-(1-7) specific receptors (or a subtype of Ang-(1-7) receptors) might be sensible (with possible high affinity) to losartan. Additional experiments are thus necessary to further clarify these interactions.
Petrescu
Gh
G
Disciplina de Fiziologie, Facultatea de Medicină, Universitatea de Medicină şi Farmacie Gr.T. Popa Iaşi.
Gurzu
B
B
Slătineanu
Simona Mihaela
SM
Costuleanu
M
M
Costuleanu
Natalia
N
D000465:Algorithms; D000803:Angiotensin I / Q000494:pharmacology*; D000804:Angiotensin II / Q000494:pharmacology*; D000818:Animals; D000959:Antihypertensive Agents / Q000494:pharmacology*; D008297:Male; D009131:Muscle, Smooth, Vascular / Q000187:drug effects; D010446:Peptide Fragments / Q000494:pharmacology*; D011169:Portal Vein / Q000187:drug effects*; D051381:Rats; D017208:Rats, Wistar; D014662:Vasoconstrictor Agents / Q000494:pharmacology*
D000959:Antihypertensive Agents; D010446:Peptide Fragments; D014662:Vasoconstrictor Agents; D000804:Angiotensin II; D000803:Angiotensin I; C118790:angiotensin I (1-7)