AVE 0991, a Nonpeptide Mimic of the Effects of Angiotensin-(1–7) on the Endothelium

Abstract

Recently, we demonstrated that the heptapeptide angiotensin-(1–7) (Ang-[1–7]) exhibits a favorable kinetic of nitric oxide (NO) release accompanied by extremely low superoxide (O ₂ ⁻ ) production. In this report we describe AVE 0991, a novel nonpeptide compound that evoked effects similar to Ang-(1–7) on the endothelium. AVE 0991 and unlabeled Ang-(1–7) competed for high-affinity binding of [ ¹²⁵ I]-Ang-(1–7) to bovine aortic endothelial cell membranes with IC ₅₀ values of 21±35 and 220±280 nmol/L, respectively. Stimulated NO and O ₂ ⁻ release from bovine aortic endothelial cells was directly and simultaneously measured on the cell surface by selective electrochemical nanosensors. Peak concentrations of NO and O ₂ ⁻ release by AVE 0991 and Ang-(1–7) (both 10 μmol/L) were not significantly different (NO: 295±20 and 270±25 nmol/L; O ₂ ⁻ : 18±2 and 20±4 nmol/L). However, the released amount of bioactive NO was ≈5 times higher for AVE 0991 in comparison to Ang-(1–7). The selective Ang-(1–7) antagonist [D-Ala ⁷ ]-Ang-(1–7) inhibited the AVE 0991–induced NO and O ₂ ⁻ production by ≈50%. A similar inhibition level was observed for the Ang II AT ₁ receptor antagonist EXP 3174. In contrast, the Ang II AT ₂ receptor antagonist PD 123,177 inhibited the AVE 0991–stimulated NO production by ≈90% but without any inhibitory effect on O ₂ ⁻ production. Both NO and O ₂ ⁻ production were inhibited by NO synthase inhibition (≈70%) and by bradykinin B ₂ receptor blockade (≈80%). AVE 0991 efficiently mimics the effects of Ang-(1–7) on the endothelium, most probably through stimulation of a specific, endothelial Ang-(1–7)-sensitive binding site causing kinin-mediated activation of endothelial NO synthase.