title: Induction of DNA repair synthesis by ultraviolet radiation and methylmethanesulphonate in cultured mouse lymphocytes.
abstract: The induction of DNA repair synthesis by UV-radiation and methyl-methanesulphonate (MMS) was studied in mouse lymphocytes and leukemic cells by means of autoradiography and scintillation counting, after labelling in vitro with tritiated thymidine ([3H]dThd). Repair stimulation was detected by both procedures in LSTRA and YC8 leukemic cell lines as well as in primary fibroblasts of BALB/c and BALB/Mo mice. No stimulation was observed in primary cultures of lymphocytes from the spleen, thymus and lymph-nodes of the same mice. In primary lymphocytes neither stimulation with concanavalin A (Con A) nor pre-incubation with 5-bromodeoxyuridine (BUdR) were effective in making evident DNA repair. The data put into question the reliability of the repair test for the prediction of carcinogenic potential of chemicals.
mesh_terms: D000818:Animals; D001345:Autoradiography; D002460:Cell Line; D002478:Cells, Cultured; D004247:DNA / Q000096:biosynthesis; D004260:DNA Repair / Q000187:drug effects / Q000528:radiation effects; D005347:Fibroblasts / Q000187:drug effects / Q000528:radiation effects; D007942:Leukemia, Experimental / Q000378:metabolism; D008214:Lymphocytes / Q000187:drug effects / Q000378:metabolism* / Q000528:radiation effects; D008741:Methyl Methanesulfonate / Q000494:pharmacology*; D051379:Mice; D008807:Mice, Inbred BALB C; D014466:Ultraviolet Rays
chemical_list: D004247:DNA; D008741:Methyl Methanesulfonate