Effects of nicotinamide on NAD and poly(ADP-ribose) metabolism in DNA-damaged human lymphocytes.
The effect of nicotinamide on unscheduled DNA synthesis was studied in resting human lymphocytes. In cells treated with UV irradiation or with MNNG, nicotinamide caused a two-fold stimulation of unscheduled DNA synthesis and retarded the rate of NAD+ lowering caused by these treatments. Nicotinamide also reduced the burst of poly(ADP-ribose) synthesis caused by MNNG treatment. Thus under conditions that it enhances unscheduled DNA synthesis, nicotinamide causes marked effects on the metabolism of NAD+ and poly(ADP-ribose). The effect of nicotinamide on unscheduled DNA synthesis was shown to be independent of protein or polyamine synthesis.
D004260:DNA Repair; D004261:DNA Replication / Q000187:drug effects*; D006801:Humans; D007700:Kinetics; D008214:Lymphocytes / Q000378:metabolism*; D008769:Methylnitronitrosoguanidine / Q000494:pharmacology; D009243:NAD / Q000378:metabolism*; D009536:Niacinamide / Q000494:pharmacology*; D009702:Nucleoside Diphosphate Sugars / Q000378:metabolism*; D011064:Poly Adenosine Diphosphate Ribose / Q000378:metabolism*
D009702:Nucleoside Diphosphate Sugars; D009243:NAD; D008769:Methylnitronitrosoguanidine; D009536:Niacinamide; D011064:Poly Adenosine Diphosphate Ribose