title: Effect of excess methionine on methotrexate cell-killing action in vitro.
abstract: Methionine at the concentrations 10, 15 and 20 times higher than in complete Fischer's medium produced a transient impairment or a transient block in the growth of L 5178 Y cells in culture without influencing their viability. Autoradiographic data revealed that methionine-induced inhibition of DNA synthesis was followed by a partial synchronization of cells in the phase of DNA synthesis. Methionine at a high concentration (1.5 mg/ml) enhanced the cell-killing action of methotrexate under conditions of delayed drug addition and did not diminish it when added with the drug simultaneously.
mesh_terms: D000818:Animals; D002455:Cell Division / Q000187:drug effects; D002478:Cells, Cultured; D003470:Culture Media; D004247:DNA / Q000096:biosynthesis; D004357:Drug Synergism; D008715:Methionine / Q000494:pharmacology*; D008727:Methotrexate / Q000378:metabolism / Q000494:pharmacology*; D051379:Mice
chemical_list: D003470:Culture Media; D004247:DNA; D008715:Methionine; D008727:Methotrexate