[Changes in the cytochemical and morphometric characteristics of the myocytes in the right heart of the rat in adrenal-regeneration hypertension].

A study was made on myocytes of the right atrium and the right ventricle of rats with experimental arterial hypertension due to adrenal regeneration. The nuclear DNA and the total protein in the cytoplasm were revealed using two consecutive tests: the Feulgen reaction and Napththol yellow S staining. A two-wavelength scanning cytophotometry was used for measuring DNA and protein contents. It has been ascertained that the polyploidy levels in the myocytes of the right atrium and the right ventricle, measured 6, 12 and 26 weeks after nephradrenalectomy by the Skelton technique, differ from the control level negligibly. A small increase in the share of tetraploid myocytes occurred in 12 weeks in the right atrium, and in 26 weeks in the right ventricle. The mean nuclear volume in atrial myocytes decreased gradually within 12 weeks, to increase afterwards but did not reach to control level in 26 weeks. The cytoplasm volume of atrial myocytes decreased in 6 weeks, and then was seen to increase gradually approaching the norm within 26 weeks. At the same time the mean cytoplasm volume of ventricular myocytes, which remained practically unchanged within 6 weeks, decreased within 12 weeks more than twice as compared to the control level, but in 26 weeks started to rise, although less quickly than the volume of atrial myocytes. The common protein content was seen to decrease 6 weeks after the operation both in atrial and ventricular myocytes, then gradually approached the control within 26 weeks, these changes in atrial myocytes being sharper than in ventricular myocytes.