title: 5-fluorouracil uptake by irradiation perturbed tumor.
abstract: An in vitro system was used to study the uptake of 5-fluorouracil by LSA ascites tumor cells. Changes in drug uptake with cell age and following a 1,000-rad radiation perturbation of the cell population were studied. DNA synthesis and drug uptake were highest during early rapid tumor growth and decreased with tumor age and stationary phase. Radiation perturbation by 1,000 rad caused a second peak of cellular DNA synthetic activity and drug uptake. These results indicate that irradiation stimulated regrowth activity of tumor in vivo after the 1,000-rad exposure. In vivo survival time changes of stationary phase tumor after in vivo irradiation correlated with the vitro assay data. This indicates that combined treatment modalities depends in part on the regrowth of tumor after tumor cell killing.
mesh_terms: D000818:Animals; D002286:Carcinoma, Ehrlich Tumor / Q000188:drug therapy / Q000378:metabolism* / Q000532:radiotherapy; D004273:DNA, Neoplasm / Q000096:biosynthesis / Q000528:radiation effects; D005472:Fluorouracil / Q000378:metabolism* / Q000528:radiation effects / Q000627:therapeutic use; D051379:Mice; D008810:Mice, Inbred C57BL; D013997:Time Factors
chemical_list: D004273:DNA, Neoplasm; D005472:Fluorouracil