A synthetic peptide antagonist of the bradykinin B2 receptor (IC50 = 1.07 nM; Ki = 0.798 nM); inhibits bradykinin-induced contractions in isolated guinea pig ileum and pulmonary arteries as well as in rat uterus (IC50s = 11, 5.4, and 4.9 nM, respectively); inhibits bradykinin-induced bronchoconstriction in a guinea pig model (ID50s = 13.4 and 31.8 pmol/kg, i.v., for pulmonary resistance and dynamic lung compliance, respectively); reduces vascular permeability in a mouse model of hereditary angioedema (30 μg, i.v.)