The plateau of the action potential of the frog ventricle.

A study was made of the change's produced in action potentials of frog ventricular cells by variation in ion concentrations, by administration of NaN3, 2: 4 DNP, NaCN, NalA and N2 which shortened the potentials. The exposure of the perfused tissue to ionized acridines, barbiturates and desoxyglucose caused a prolongation of the action potentials. These actions as obtained were reversible. The evidence from the time-course and differential effects of inhibitors suggests that an active ion transport, modulated by Ko + may be important in maintaining the plateau phase of the action potential.