Metabolic Aspects of the Relationship Between the Contractility and Membrane Potentials of the Rat Atrium

Some of the relationships between metabolism, membrane potentials and contractility in cardiac tissue have emerged from a study of the effects of anoxia, depletion of substrate and dinitrophenol on the rat atrium. The repolarization phase of the action potential was shown to be particularly sensitive to disturbances in metabolism. Depression of metabolism resulted in a more rapid repolarization, which may provisionally be interpreted as an acceleration of K+ efflux; restoration of metabolism reversed this effect. A concept relating membrane potentials and metabolism is presented, involving the presence of bound ATP within the membrane.