[Mitochondrial oxidation and ultrastructure of the myocardium on a background of incorporation of cesium radionuclides].
Parameters of the mitochondrial oxidation and ultrastructure of the myocardium in white rats were studied on a background of consumption of food supplemented with 137Cs at 60 or 600 Bq/kg (calculated doses were 1.5 and 15 microGy, respectively). The observed stimulation of the respiratory activity in myocardial samples cultivated on endogenous and several exogenous substrates was found to reduce the effectiveness of energy production by dissociation of oxidative phosphorylation and disruption of macroerg deposition in the form of creatine phosphate. Ultrastructural findings included swelling of mitochondria, matrix clarification, partial reduction of the number of crists, and myeline-like bodies in the matrix. Observed were high nucleus structural polymorphism with extension of the perinuclear space, spotted distribution of chromatin, and modification of the myofibril structure. These morphofunctional changes can be considered as reflection of apoptosis associated with activation of peroxidation.