Distribution of cardiomyocytes in cell cycle during aging

Nino Tevzadze

Department of Histology, Cytology and Embryology, Tbilisi State Medical University, Georgia

Cell cycle activity is an intrinsic component of cardiac differentiation and morphogenesis. In this study isolated mice hearts were used to investigate the effects of age on cardiomyocytes’ cell cycle under normal physiological conditions in vivo. Number of diploid, tetraploid, polyploid (octaploid, 16n and 32n), apoptotic nuclei and nuclei in S phase were counted by a Becton Dickinson (Mountain Vieu, CA) FACScan flow cytometer. It has been considered, that in all studied age groups during of cell cycle are identical. However, in adults comparatively to juvenile mice simultaneously increases the amount of polyploid and apoptotici nuclei. At the same time the quantity of apoptotic nuclei remains high in senescent mice. Herewith, the amount of polyploid nuclei decreases in this group. Also, according to our experimental data the capacity of re-initation of DNA synthesis in the heart is low. However, the fact of DNA synthesis per se seems to be insufficient to drive adult cardiomyocytes through cell division. So, we can consider, that the heart has low regenerative potential.

Keywords:  cardiomyocyte, cell cycle, apoptosis