We have developed a series of peptide heterodimers based on the B2 antagonist~-Are- [Hyp~,~-Phe7, Leu8]-BK (1) and the B1 antagonist LysO-[Leus, des-Arg91-BK (7) that are potent antagonists of both B1 and B2 receptors. From this series, compound 50 (alternatively, CP-0364), the 1, 6-bis (succinimido) hexane heterodimer of~-ArgO-[Hyp~, Cys~,~-Phe~, Leu~ l-BK (2), and D-ArgO-[Cysl,-Hyp3, Leu8, des-Argg]-BK (6), was found ...