[Shifts in the electrolyte and energy metabolism of rat myocardium in experimental hypercorticism].

Experiments were conducted on 612 albino male rats; a complex study was made in the myocardium of K+, Na+, Ca2+, Mg2+, Cl-, water, creatinphosphate, inorganic phosphorus, adenylic system components. A study was made of the effect of exogenous hypercorticism created by the administration of prednisolone, hydrocortisone and DOCA on the cardiac metabolism. Potassium-sodium tissue homeostasis in the myocardium proved to be stable under these conditions. Glucocorticoid hypercorticism was characterized by a reduction of creatinphosphate and by the accumulation of inorganic phosphate. DOCA administration failed to be significantly reflected on the balance of the phosphate macroerg balance. Glucocorticosteroids caused an increase in the Mg2+ and a reduction of the Cl- level, whereas DOCA brings about an increase of Ca2+ and Cl- in the myocardium. Dosaged sharp physical load is accompanied by the K+ cumulation in the myocardium. In the case of 2-hour swimming this is combined with a "stable" condition of the energy processes. When swimming is continued up to 5 hours there occurs a distinct disturbance of the balance of disintegration and resynthesis of the phosphate macroergs in the cardiac muscle. Administration of the corticosteroids under study against this background produced no significant influence on the character of the shifts in the electrolyte-energy metabolism, and failed to prevent the normal course of the restorative processes in the myocardium at the immediate period after the exercises.