title: Unscheduled synthesis of DNA and poly(ADP-ribose) in human fibroblasts following DNA damage.
abstract: Unscheduled DNA synthesis has been measured in human fibroblasts under conditions of reduced rates of conversion of NAD to poly)ADP-ribose). Cells heterozygous for the xeroderma pigmentosum genotype showed normal rates of UV induced unscheduled DNA synthesis under conditions in which the rate of poly(ADP-ribose) synthesis was one-half the rate of normal cells. The addition of theophylline, a potent inhibitor of poly(ADP-ribose) polymerase, to the culture medium of normal cells blocked over 90% of the conversion of NAD to poly(ADP-ribose) following treatment with UV or N-methyl-N'-nitro-N-nitro-soguanidine but did not affect the rate of unscheduled DNA synthesis.
mesh_terms: D002460:Cell Line; D004247:DNA / Q000096:biosynthesis*; D004260:DNA Repair; D004261:DNA Replication / Q000187:drug effects / Q000528:radiation effects; D005347:Fibroblasts / Q000187:drug effects / Q000528:radiation effects; D005838:Genotype; D006579:Heterozygote; D006801:Humans; D008769:Methylnitronitrosoguanidine / Q000494:pharmacology; D009702:Nucleoside Diphosphate Sugars / Q000096:biosynthesis*; D011064:Poly Adenosine Diphosphate Ribose / Q000096:biosynthesis*; D014466:Ultraviolet Rays; D014983:Xeroderma Pigmentosum / Q000378:metabolism
chemical_list: D009702:Nucleoside Diphosphate Sugars; D008769:Methylnitronitrosoguanidine; D011064:Poly Adenosine Diphosphate Ribose; D004247:DNA