Capillary system of rat myocardium in experimental hypertrophy and physical exercise.

The authors investigated in 90 albino rats, by means of a new non-injection method, the morpho-functional state of the capillary system in various parts of the myocardium in a normal state, in hypertrophy of varying degree and during physical exercise. It was found that the density, the surface are (CSA) and the capacity of the capillary bed of the right ventricle are larger than in the left ventricle. The increase in capillary blood supply in a hypertrophic myocardium occurs in parallel with the development of the hypertrophy and at rest fully corresponds to the increased myocardial mass. However, at maximal physical load the capillary segment of blood supply to the myocardium functions insufficiently, which is evidenced by a decrease in the working capacity of the experimental animals.