HUMAN FETAL VENTRICULAR CARDIOMYOCYTES IN VITRO: PROLIFERATION AND
DIFFERENTIATION
I. L. Erokhina,1 E. G. Semenova, O. I, Emelyanova
Institute of Cytology RAS, St. Petersburg, Russia;
1 e-mail: hcartdcv@mail.cytspb.rssi.ru
In this study, in the primary cell culture of human fetal cardiomyocytes proliferation of myocytes combines with
their differentiation. The cells were isolated enzymatically from 19-22 week-old human fetuses and cultured for 14 days. DNA
synthesis, ultrastracture and presence of atrial natriuretic peptide (ANP) were examined. In 7 day-old culture, the myocytes make
about 60%, in 14 day-old culture - about 50%. Myocytes synthesize DNA and divide mitotically. After a 24 h incubation with
3H-thymidine in 7 day-old culture 1.8 ± 0.5 % of muscle and 25.2 ± 11.7 % of non-muscle cells are labeled, in 14 day-old
culture - 2.5 ± 0.5 and 8.1 ± 1.7 % of cells are labeled, respectively. In 7 and 14 day-old cultures the degree of redifferentiation
of contractile apparatus in myocytes varies from scattered actin and myosin filaments surrounded by ribosomes to differentiating
rnyofibrils with distinct sarcomeres and Z-discs. Single electron-dense granules, morphologically similar to secretory atrial
granules, display ANP-immunoreactivity. Thus, human fetal ventricular cardiomyocytes in cell culture proliferate, differentiate
and synthesize ANP for 14 days; this is indicative of vitality of these cells.
Key words: ventricular cardiomyocytes, human fetuses, cell culture, DNA synthesis, ultrastructure, ANP
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