[Ultrastructure of the sinus and atrioventricular nodes in experimental myocardial infarct].

The ultrastructure of sinus and atrioventricular nodes was studied in white rats with experimental myocardial infarction. 24 hours after the induction of the disease mitochondrial enlargement characterized by the increase in their area, decrease in the number of cristae and the decline in the rate of mitochondrial energy effectiveness was detected. Different degrees of nuclear chromatin aggregation and membrane permeability for colloidal lanthanum were observed. Characteristic types of conduction cellular lesions were revealed in experimental myocardial infarction.