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Poly(ADP-ribose) polymerase activity and DNA strand breaks are affected in tissues of niacin-deficient rats.
- Source :
-
The Journal of nutrition [J Nutr] 1993 Aug; Vol. 123 (8), pp. 1349-55. - Publication Year :
- 1993
-
Abstract
- The niacin cofactor, NAD, is the substrate for poly(ADP-ribose) polymerase, an enzyme associated with DNA repair. We investigated, therefore, whether hepatic poly(ADP-ribose) polymerase activity was altered and DNA strand breaks in lymphocytes and liver were greater in niacin-deficient rats. A niacin deficiency was established in weanling rats with diets containing 1.5 mg/kg of niacin. Based on lower growth rates and NAD concentrations in blood, liver and skeletal muscle, this diet maintained rats in a deficient state for 1 mo, and, when the dietary niacin was reduced to 0.5 mg/kg, rats remained deficient for an additional month. The hepatic poly(ADP-ribose) polymerase activity was decreased in one experiment when mean hepatic NAD concentrations were 0.60 and 0.51 mumol/g at d 34 and d 60, respectively, compared with 0.77 and 0.80 mumol/g in pair-fed controls. Enzyme activity, however, was greater than in controls when hepatic NAD concentrations were < 0.30 mumol/g. Strand breaks in DNA did not accumulate except after tissues were exposed to hypoxanthine-xanthine oxidase, a free radical-generating system. Exposure to this system caused more DNA strand breaks in lymphocytes and hepatic nuclei from niacin-deficient rats compared with the same tissues from controls. The results suggest that, in rats, although hepatic poly(ADP-ribose) polymerase activity can be elevated, a severe niacin deficiency may increase the susceptibility of DNA to oxidative damage, likely due to a lower availability of NAD.
- Subjects :
- Animals
Body Weight
Eating
Liver chemistry
Liver enzymology
Liver pathology
Lung chemistry
Lung pathology
Lymphocytes chemistry
Lymphocytes pathology
Male
Muscles chemistry
Muscles pathology
NAD analysis
NAD blood
Rats
Rats, Sprague-Dawley
Spleen chemistry
Spleen pathology
Tryptophan administration & dosage
Vitamin B Deficiency enzymology
Vitamin B Deficiency pathology
Weight Gain
DNA Damage
Niacin deficiency
Poly(ADP-ribose) Polymerases metabolism
Subjects
Details
- Language :
- English
- ISSN :
- 0022-3166
- Volume :
- 123
- Issue :
- 8
- Database :
- MEDLINE
- Journal :
- The Journal of nutrition
- Publication Type :
- Academic Journal
- Accession number :
- 8336204
- Full Text :
- https://doi.org/10.1093/jn/123.8.1349