Inhibition of repair patch ligation by an inhibitor of poly(ADP-ribose) synthesis in normal human fibroblasts damaged with ultraviolet radiation

Journal Article · Tue Mar 01 04:00:00 EST 1988 · Mol. Pharmacol.; (United States)

OSTI ID:7025290

Hunting, D J; Gowans, B J

The effect of inhibiting poly(ADP-ribose) synthesis on DNA excision repair following UV irradiation of cultured normal human fibroblasts was determined under conditions which did not perturb NAD+ concentration. Following UV irradiation, there was a transient increase in DNA strand breaks to a maximum of 800 rad eq of breaks 30 min after damage. 3-Aminobenzamide (5 mM) caused a 50% increase in the maximum number of DNA single strand breaks following damage but did not prevent the decline in strand breaks which normally occurs within the first hour after damage. Addition of 3-aminobenzamide several hours after damage, when most of the strand breaks had disappeared, caused a reaccumulation of strand breaks. 3-Aminobenzamide inhibited ligation of repair patches, as measured by exonuclease III, following damage by UV radiation and the magnitude of the inhibition was sufficient to account for the increases in strand breaks caused by 3-aminobenzamide. UV radiation alone did not lower NAD+ concentrations; however, when the repair synthesis step was inhibited by aphidicolin and hydroxyurea, the number of single strand breaks increased and the NAD+ concentration fell to 11%. 3-Aminobenzamide inhibited this depletion of NAD+ by 80%.

• Research Organization: Univ. of Sherbrooke, Quebec (Canada)
• OSTI ID: 7025290
• Journal Information: Mol. Pharmacol.; (United States), Journal Name: Mol. Pharmacol.; (United States) Vol. 33:3; ISSN MOPMA
• Country of Publication: United States
• Language: English

Related Subjects

560120* -- Radiation Effects on Biochemicals
Cells
& Tissue Culture
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
AMIDES
ANIMAL CELLS
ANIMALS
BIOLOGICAL EFFECTS
BIOLOGICAL RADIATION EFFECTS
BIOLOGICAL RECOVERY
BIOLOGICAL REPAIR
COENZYMES
CONNECTIVE TISSUE CELLS
DNA REPAIR
ELECTROMAGNETIC RADIATION
FIBROBLASTS
GENETIC EFFECTS
GENETIC RADIATION EFFECTS
INHIBITION
MAMMALS
MAN
NAD
NUCLEOTIDES
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PRIMATES
RADIATION EFFECTS
RADIATIONS
RADIOINDUCTION
RADIOSENSITIVITY EFFECTS
RECOVERY
REPAIR
SOMATIC CELLS
STRAND BREAKS
ULTRAVIOLET RADIATION
VERTEBRATES