[Calcium accumulating ability of various membrane structures of the myocardium in experimental coronary insufficiency].

Disturbances in properties of the sarcoplasmic reticulum (SR) Ca-pump are found under conditions of experimental coronary insufficiency and confirmed by a decrease in the Ca2+-ATPase activity and in ability to the 45Ca uptake by SR membranes. Simultaneously the Ca2+ uptake by mitochondria increases. It is established that a rise in the total Ca content in the myocardium tissue is accompanied by its redistribution between the subcellular membrane structures and its accumulation in mitochondria. The found shifts may underlie disturbances in energy supply and a decrease in the contractile myocardium function with ischemia.