title: Analysis of population cytokinetics of chick myocardial cells in tissue culture.
abstract: The growth of embryonic chick cardiac myocytes and fibroblasts in tissue culture was evaluated by the kinetics of nuclear labeling during continuous exposure to [3H]thymidine. The fraction of mitotically active cells, the mean intermitotic period and the population doubling times were determined in each cell type during 3 weeks in culture. After 24 hr in culture, 90% of the muscle cells were mitotically active with minimal population doubling times of 65 hr. By 17 days in culture only 5% of the myocytes continued to divide with population doubling times greater than 3000 hr. Primarily, the lengthening of doubling times was due to a withdrawal of cells from the mitotic cycle and much less to a lengthening of the intermitotic period. Growth of cardiac muscle cells from embryonic hearts from 4 to 10 days of development was also compared. Muscle cells from younger hearts displayed greater mitotic activity than those from older hearts at equivalent times in culture.
mesh_terms: D000818:Animals; D002455:Cell Division / Q000187:drug effects; D002478:Cells, Cultured; D002642:Chick Embryo; D005347:Fibroblasts / Q000166:cytology; D005973:Glutamine / Q000494:pharmacology; D006321:Heart / Q000196:embryology*; D007700:Kinetics; D008938:Mitosis / Q000187:drug effects; D009206:Myocardium / Q000166:cytology*; D013936:Thymidine / Q000378:metabolism / Q000494:pharmacology; D013997:Time Factors
chemical_list: D005973:Glutamine; D013936:Thymidine