BLOCKING OF THE IN VIVO EFFECTS OF BRADYKININ AND KALLIDIN WITH CARBOXYPEPTIDASE B

¹ Mellon Institute and Departments of Pharmacology and Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania

Intravenous injection of carboxypeptidase B abolished or very much decreased the hypotension caused by bradykinin, kallidin, 6-glycine bradykinin or kallikrein. The experiments were done on guinea pigs, rabbits or cats. The administration of the enzyme preparation did not block the effects of histamine and eledoisin. Subcutaneous injection of carboxypeptidase B also prevented in part the capillary permeability changes caused by intradermal injection of bradykinin in guinea pigs. The decrease in the circulating enzyme level and return of bradykinin effect in rabbits and cats were correlated. The results were explained by the very rapid in vivo inactivation of those peptides which have a C-terminal arginine.