Changes in the deoxyribonucleoside triphosphate pools of mouse 5178Y lymphoma cells following exposure to methotrexate or 5-fluorouracil.

Abstract

Changes are reported in the deoxyribonucleoside triphosphate pools of L5178Y cells during their exposure to methotrexate or 5-fluorouracil. For both drugs the intracellular deoxythymidine triphosphate level fell rapidly, accompanied by an increase in deoxycytidine triphosphate concentration. These changes were associated with increases in the levels of deoxyadenosine triphosphate and deoxyguanosine triphosphate, which were marginal in methotrexate-containing cultures but considerable in cultures containing 5-fluorouracil. The possible significance of these events is discussed in relation to the presently accepted mechanisms responsible for the cytotoxicity of methotrexate and 5-fluorouracil.