Abstract: | The ultrastructure of myocytes of the rat myocardium and skeletal muscles was studied in the control during physical exercise and under conditions of two-week sodium hydroxybutyrate pretreatment. It was shown that single maximum physical exercise caused significant changes in the fine structure of cardiomyocytes and somewhat less changes in a pronounced intermyofibrillar edema, the swelling of mitochondria and an acute fall of the glycogen level. A two-week sodium hydroxybutyrate pretreatment prevented the changes in the myocytes. The observed structure normalization induced by the drug is likely to be due to the specific nature of its metabolic transformation and to the effect on the energy exchange. |