[Ion-transport system and various components of sarcolemma structure during acute myocardial ischemia]

Ion transport properties and some components of lipid structure in myocardial sarcolemma were studied under conditions of short-term acute ischemia simulated in rabbits by means of intravenous administration of vasopressin at a dose of 0.2 U/kg. The acute coronary insufficiency was accompanied by distinct alterations in the parameters specific for calcium metabolism and transport: activity of Na+, K+-ATPase and the rate of Na+Ca2+ turnover were decreased, while 45Ca-binding ability and content of Ca2+ were increased in the myocardial sarcolemma. Alterations in lipid structure, phospholipid composition of membranes and accumulation of free fatty acids appear to be responsible for the phenomenon observed. The increased rate of calcium ions transport found may occur due to alterations in the sarcolemma structure.