抄録
Human diploid cell strains had tissue- or organ-specific lifespans depending on differences in the sources of cells. In most of the previous studies on the lifespan of embryonic chick cells, mixtures of different tissues and organs were used as the source of cells. In the present study, the lifespans of femur chondrocytes and cardiac muscle cells obtained from the same 13-day chick embryos were compared under identical serial cultivations. Chondrocytes divided more rapidly than cardiac muscle cells. The average increasing rates of chondrocytes per day stayed at levels of more than 1.0 for first 8 passages. On the other hand, those of cardiac muscle cells were at levels of more or less than 0.5 for 11 passages. The cell cycle time of the former was about half that of the latter. The average cell cycle times of chondrocytes were 27-51 h in the first 7 passages, whereas those of cardiac muscle cells were 53-97 h in the first 5 passages. The number of population doublings (PDs) of chondrocytes was 29.6 with 19 passages in cultivation for 98 days, whereas PDs of cardiac muscle cells was 13.3 with 13 passages for 85 days. This may be the first report to compare the lifespans of chondrocytes and cardiac muscle cells of the embryonic chick.
