[Ultrastructural changes in cardiomyocytes and heart muscle capillaries after vagotomy and physical exertion].

Electron microscopic studies of the changes in cardiomyocytes and capillaries of the cardiac muscle were performed in white mice after partial extracardiac parasympathectomy and graded physical exercise. It has been established that submaximum physical exercise leads to slight ultrastructural alterations in the left ventricular cardiomyocytes and capillaries. Maximum physical exercise in intact animals is followed by still greater ultrastructural changes in the heart muscle. Swelling of mitochondria with the focal destruction of crysts, widening of sarcoplasmic reticular cisterns, disturbance of sarcomer to mitochondrion ratio, endotheliocyte edema and narrowing of the capillary lumen are observed. In vagotomized animals fulfilling running exercises of submaximum load dystrophic changes in cardiomyocytes and capillaries are noted only at early stages (day 7). Maximum physical exercise in animals with disturbed integrated nerve influences promotes the development of focal destructive changes in the myocardium.