The bradykinin potentiating activity of two pentapeptides on various isolated smooth muscle preparations

Two bradykinin potentiating peptides A-VI5 (Val-Glu-Ser-Ser-Lys) and BPP5a (Pyr-Lys-Trp-Ala-Pro), were compared with respect to their potentiation of a number of different bradykinin effects on six isolated smooth muscle preparations. Apart from the considerable difference in effective concentrations, no essential qualitative difference was observed between these two peptides. Therefore the assumption of a different mechanism of action for the two peptides, which have a completely different structure, could not be substantiated.