The calcium paradox: metabolic, electrophysiological, contractile and ultrastructural characteristics in four species.

The effect of transient depletion and repletion of calcium upon the electrophysiological activity, contractile activity, coronary flow, tissue energy metabolism and the cellular leakage of metabolites and creatine kinase has been characterized in the rat heart and now has been compared with the mouse, guinea pig and rabbit heart. The sudden and massive damage (the calcium paradox) which occurred in the rat was observed in all species studied. While fine differences between species were detectable, the basic principles and damaging effects of sudden transmembrane calcium fluxes would appear to be common to all species.