[The effect of adrenal-regeneration hypertension on protein-nucleic acid metabolism in rat atrial cardiomyocytes].

A study was made on cardiomyocytes of the left atrium 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 Naphthol yellow S staining. The two-wavelength scanning cytophotometry was used for measuring DNA and protein contents. It has been ascertained that the polyploidy level in the nuclei of the left atrium myocytes, measured 6 and 9 weeks after nephradrenalectomy, remained the same as in the intact animals. The increase in the share of tetra- and octaploid nuclei occurred by 12 weeks. The mean nuclear volume decreased gradually throughout 9 weeks and subsequently was seen to increase, but by 12 weeks it did not yet reach the control level. The cytoplasm volume decreased by 6 weeks, then started to increase by 9 weeks to reach almost the standard level. The common protein content in the atrial myocytes decreases also by 6 weeks, but restores more rapidly than the volume, and reaches the standard level by 9 weeks, exceeding the same by 12 weeks. Thus, the prolonged hyperfunction of the atrial cardiomyocytes, associated with arterial hypertension, results in their hypertrophy which becomes apparent both in the increased polyploidy and in the augmented protein mass of the cells.