title: The in vitro kinetics of senescence of Fischer 344 rat embryo fibroblasts.
abstract: The kinetics of replicative senescence have been determined in three independent cultures of fibroblasts derived from Fischer rat embryos (FREF). In each case the growth fraction was measured by immunocytochemical staining for proliferating cell nuclear antigen (PCNA) and by metabolic labeling using bromodeoxyuridine (BrdU). FREF cultures entered senescence at an average of 20.4 population doublings. The growth fraction declined smoothly as measured by both kinetic techniques. The average rate of decline of the growth fraction observed using BrdU was -0.79 +/- 0.12% population doubling(-1) which was closely comparable to the loss of PCNA reactivity (-0.80 +/- 0.11% population doubling(-1)). We conclude that senescence in FREF cultures occurs as the result of a progressive loss of the culture growth fraction rather than a sudden abrupt collapse.
authors.affiliation: University of Brighton, Brighton, East Sussex, UK. rgaf@brighton.ac.uk
authors.forename: Richard G A
authors.initials: RG
authors.lastname: Faragher
authors.forename: Ian R
authors.initials: IR
authors.lastname: Kill
mesh_terms: D000818:Animals; D001973:Bromodeoxyuridine / Q000378:metabolism; D049109:Cell Proliferation; D002478:Cells, Cultured; D016922:Cellular Senescence; D004622:Embryo, Mammalian / Q000166:cytology; D005347:Fibroblasts / Q000378:metabolism / Q000502:physiology*; D007700:Kinetics; D018809:Proliferating Cell Nuclear Antigen / Q000378:metabolism; D051381:Rats; D011916:Rats, Inbred F344
chemical_list: D018809:Proliferating Cell Nuclear Antigen; D001973:Bromodeoxyuridine