title: Species variation in BrdUrd-induced sister-chromatid exchanges.
abstract: Peripheral blood lymphocytes from cattle, pigs, sheep and humans were cultured in the presence of 0.5, 1, 2, 5, 10 or 20 micrograms/ml of BrdUrd. Sister-chromatid exchanges were scored in 25 second-division metaphases from each donor at each level of the chemical. Dose--response curves for all 4 species increased steeply to 2 micrograms/ml; above this level, SCE numbers increased less rapidly but maintained a linear relationship to increasing BrdUrd concentration. Comparisons of the straight-line portions of the dose--response curves showed human cells to be significantly more sensitive to increasing BrdUrd level than cow or pig cells and different from sheep at the 10% level of confidence.
mesh_terms: D000818:Animals; D001973:Bromodeoxyuridine / Q000494:pharmacology*; D002417:Cattle; D002478:Cells, Cultured; D002842:Chromatids / Q000187:drug effects*; D003434:Crossing Over, Genetic; D006801:Humans; D008214:Lymphocytes / Q000648:ultrastructure; D009153:Mutagens; D012756:Sheep / Q000235:genetics; D012854:Sister Chromatid Exchange; D013045:Species Specificity; D013552:Swine / Q000235:genetics
chemical_list: D009153:Mutagens; D001973:Bromodeoxyuridine