Myocardial creatine phosphate and nucleotides in anoxic cardiac arrest and recovery

¹ Departments of Laboratory Medicine and Surgery, University of Minnesota; and Hill Foundation Research Laboratory, Ancker Hospital, St. Paul, Minnesota

In isolated perfused dog hearts, myocardial concentrations of creatine phosphate (CrP) and adenosine triphosphate (ATP) decreased following a 45-min period of anoxia. After partial resuscitation by perfusion of oxygenated blood for 30 min, CrP had risen again to approximately control values but ATP concentration had fallen lower. Increased concentrations of deaminated derivatives of ATP, chiefly inosine, were found in the myocardium and in the perfusion effluent after anoxia. The myocardial inosine was still elevated after resuscitation. We conclude that the dynamic equilibrium involving breakdown and resynthesis of ATP through deamination and reamination is disturbed by periods of anoxia as carried out in these experiments and, in addition, inosine is lost by diffusion into extracellular compartments.