title: Effects of [3H]UdR on the cell-cycle progression of L1210 cells.
abstract: Tritium-labelled uridine [( 3H]UdR) perturbs progression of L1210 cells through the mitotic cycle. The main effect manifests as a slowdown or arrest of a portion of cells in G2 and is already observed 2 hr after addition of 0.5-5.0 microCi/ml of [3H]UdR into cultures. At 2.5-5.0 microCi/ml of [3H]UdR a slowdown of cell progression through S is also apparent. Additionally, there is an increase in the number of cells with DNA values higher than 4C in cultures growing in the presence of [3H]UdR for 8-24 hr. A pulse of [3H]UdR of 2 hr duration labels predominantly (95%) cellular RNA. The first cell-cycle effects (G2 slowdown) are observed when the amount of the incorporated [3H]UdR is such that, on average there are fewer than thirty-six [3H] decays per cell which corresponds to approximately 12-19 rads of radiation. The S-phase slowdown is seen at a dose of incorporated [3H]UdR twice as high as that inducing G2 effects. The specific localization of [3H]UdR in nucleoli, peripheral nucleoplasm and in cytoplasm, as well as differences in the kinetics of the incorporation in relation to phases of the cell cycle are discussed in the light of the differences between the effects of [3H]UdR and [3H]thymidine. Mathematical modelling of the cell-cycle effects of [3H]UdR is provided.
mesh_terms: D000818:Animals; D002453:Cell Cycle / Q000187:drug effects*; D005434:Flow Cytometry; D007700:Kinetics; D007939:Leukemia L1210 / Q000473:pathology*; D008433:Mathematics; D051379:Mice; D008954:Models, Biological; D013936:Thymidine / Q000378:metabolism / Q000494:pharmacology; D014316:Tritium; D014529:Uridine / Q000378:metabolism / Q000494:pharmacology*; D014747:Vinblastine / Q000633:toxicity
chemical_list: D014316:Tritium; D014747:Vinblastine; D013936:Thymidine; D014529:Uridine