[The regulatory role of oxygen radicals in myocardial cells]

The paper reviews participation of primary active forms of oxygen in the processes of regulation of intracellular metabolism. Action of the primary forms of oxygen upon the myocardium contractile function depends on their concentration: their moderate increase enhances the rate and strength of contractions whereas higher concentrations diminish the contraction strength by inhibiting Ca2+ inflow from without. For NO the latter effect might be compensated by absence of coronary vessels dilatation. The level of the active forms of oxygen in the cells is subsidiary to the antioxidant system, and loss of the latter's components might trigger the apoptosis process and, consequently, some diseases.