ACUTE CHANGES IN HIGH-ENERGY PHOSPHATES, NUCLEOTIDE DERIVATIVES, AND CONTRACTILE-FORCE IN ISCHEMIC AND NON-ISCHEMIC CANINE MYOCARDIUM FOLLOWING CORONARY-OCCLUSION

Studies of ischemic myocardium following occlusion of coronary arterial branches revealed a substantial decline in creatine phosphate, ATP and total adenine nucleotide contents over 40 min. Contents of nucleotide breakdown derivatives increased significantly but transiently. Contractile force declined rapidly and stabilized at a low level. In non-ischemic muscle following occlusion creatine phosphate, ATP and total nucleotide contents declined rapidly, although not to the degree seen in ischemic muscle. Contents of derivatives increased only slightly. Contractile force increased.