[Contractile properties and creatine kinase activity of myofilaments after ischemia and reperfusion of the rat heart]

The state of myofibril creatinkinase and contractile properties of chemically skinned myocardial fibers of rat after 70-90 min ischemia and 15-30 min reperfusion was studied. In spite of sharp fall in the total creatinkinase activity in the tissue, the enzyme activity in myofibrils does not change greatly. Ischemia does not change the functional abilities of myofibril creatinkinase as well as characteristics of Ca-activated contraction of skinned fibers. The results show that irreversible loss of myocardial contractile activity after prolonged ischemia and reperfusion is not connected with violation of myofilament characteristics or deterioration of functional association between myofibril creatinkinase and ATPase.