Creatine phosphokinase activity in myocardial sarcoplasmic reticulum membranes in experimental coronary insufficiency

: Experiments on rats with acute coronary blood flow restriction (intravenous injection of vasopressin in a dose of 0.5 units/kg) have shown a decrease in the activity of creatine phosphokinase (CPK) and activation of lipid peroxidation in sarcoplasmic reticulum (SPR) membranes. These changes were attended by structural abnormalities in the membrane apparatus of the SPR, primarily on the part of the lipid composition. Pretreatment (1 h before vasopressin) of the animals with the antioxidant AV-156Na averted the development in the SPR membranes of the changes described. This evidences that the rate of peroxide reactions in the myocardium might determine in many respects the metabolic and structural supply of the cell apparatus.