Effect of blood serum from irradiated mice on the incorporation of DNA, RNA and protein precursor in L929 cells. A sensitive assay for measuring low dose response.
Serum from whole-body irradiated mice inhibits incorporation of DNA precursors into DNA of L929 cells in culture in a dose-dependent way. The humoral factor interfering with the incorporation of 3H-thymidine and 125I-iododeoxyuridine is identical to thymidine. The degree of depression of 125I-iododeoxyuridine-uptake is more sensitive than that of 3H-thymidine. Irradiation of donor mice does not confer a toxic effect of blood serum on cell growth in culture. Incorporation of 3H-leuchine into protein and 3H-cytidine into DNA and RNA is not affected by the serum of irradiated mice; there is no effect on the incorporation of 3H-cytidine from the intracellular precursor pool into DNA or RNA either. The present findings demonstrate the specificity and high sensitivity of the assay system for measuring thymidine concentration in mouse blood serum and point to possible applications of analysing abnormalities in DNA metabolism resulting in, or from, disturbances of the thymidine reutilization pathway.
D000818:Animals; D001769:Blood / Q000528:radiation effects*; D003562:Cytidine / Q000378:metabolism; D004247:DNA / Q000378:metabolism*; D003857:Deoxyuridine / Q000378:metabolism; D005260:Female; D005347:Fibroblasts / Q000378:metabolism*; D007930:Leucine / Q000378:metabolism; D051379:Mice; D012313:RNA / Q000378:metabolism*; D013936:Thymidine / Q000378:metabolism
D003562:Cytidine; D012313:RNA; D004247:DNA; D007930:Leucine; D013936:Thymidine; D003857:Deoxyuridine