title: Effect of 3-aminobenzamide on sister chromatid exchange frequency in X-irradiated cells.
abstract: To investigate whether a delay in the rejoining of radiation-induced strand breakage can lead to sister chromatid exchange formation, Chinese hamster ovary cells were prelabeled with 5-bromodeoxyuridine and X-irradiated in the presence of 3-aminobenzamide, an inhibitor of poly(ADP-ribose) polymerase. The resulting sister chromatid exchange frequencies were consistent with those expected if 3-aminobenzamide and X-ray treatments were independent and additive. A similar but much smaller additive effect was also observed in cells cultured in the presence of 3-aminobenzamide and X-irradiated immediately before the addition of bromodeoxyuridine to the culture medium. These findings support previous studies indicating that X rays are poor inducers of sister chromatid exchanges and suggest that the normally rapid resealing of DNA strand breaks does not account for this inefficiency.
mesh_terms: D000818:Animals; D001549:Benzamides / Q000494:pharmacology*; D002460:Cell Line; D006224:Cricetinae; D003412:Cricetulus; D003434:Crossing Over, Genetic / Q000187:drug effects*; D004260:DNA Repair / Q000187:drug effects; D005260:Female; D010053:Ovary; D012854:Sister Chromatid Exchange / Q000187:drug effects* / Q000528:radiation effects
chemical_list: D001549:Benzamides; C025160:3-aminobenzamide