Effects of calcium deficiency on cell membrane potentials of isolated frog hearts

Abstract

Membrane potentials were recorded in isolated frog hearts. Observations were made on the effects of calcium deficiency upon resting potential, action potential, overshoot, maximum depolarization rate and action potential contour. Calcium deficiency caused a significant fall in all observed potentials. Maximum depolarization rate was increased. Early repolarization rate was markedly decreased. Chelation of calcium caused changes indistinguishable from those caused by omission of the ion from the perfusate. These results are discussed in relation to current concepts.