Failure of Peptides (Angiotensin, Bradykinin, Substance P, Physalaemin, Met-Enkephalin) to Influence the Cardiac Action Potential

Abstract

Angiotensin, bradykinin, substance P, physalemin and met-enkephalin were tested for their ability to affect the action potential (AP) of the isolated guinea pig papillary muscle driven at 1/s and 3/s. Variables studied were height and duration of AP, dV/dt[left ventricular rate]max, half-life of recovery of dV/dtmax and refractory period. At relevant concentrations, the peptides were not effective.