RESUMEN
We have developed a series of peptide heterodimers based on the B2 antagonist D-Arg0-[Hyp3,D-Phe7,Leu8]-BK (1) and the B1 antagonist Lys0-[Leu8,des-Arg9]-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 D-Arg0-[Hyp3,Cys6,D-Phe7,Leu8]-BK (2), and D-Arg0-[Cys1,Hyp3,Leu8,des-Arg9]-BK (6), was found to be the most active both in vitro and in vivo. Compound 50 has a pA2 of 8.3 when measured against bradykinin (BK)-induced rat uterine smooth muscle contraction and an IC50 of approximately 10(-8) M against [des-Arg9]-BK-induced rabbit aorta smooth muscle contraction in vitro. Compounds such as 50 may be useful in the treatment of both subacute and chronic inflammatory disorders wherein both B2 and B1 receptors appear to contribute to the clinical manifestations of the disease.