Creatine kinase in subcellular components of the rabbit myocardium during experimental obstruction of the coronary circulation

: Acute myocardial ischemia (intravenous 0.2 U/kg vasopressin infusion) is shown to cause various changes in the creatine kinase isoenzyme activity: it decreases in mitochondria and sarcoplasmic reticulum and increases in myofibrils and cytosol, no significant alterations taking place in sarcolemma. It may be suggested that the stated changes are important components of the complex adaptational reactions which occur in the ischemic myocardium and support its main contractional function.