[The effect of potentiating factors on the bradykinine effect in vitro].

Bradykinin potentiating factors from the venom of Bothrops jajaraca and Agkistrodon halys blomhoffii potentiate the action of bradykinin at several smooth muscles. This potentiation is specific for bradykinin and has to be distinguished from an unspecific potentiation. The potentiation induced by BPF is not due to an indirect cholinergic mechanism or to a kininase inhibition in vitro. The results suggest that there would be an allosteric transition of the bradykinin receptor.