title: Development of a cloning assay with high cloning efficiency to detect induction of 6-thioguanine-resistant lymphocytes in spleen of adult mice following in vivo inhalation exposure to 1,3-butadiene.
abstract: A cloning assay with high cloning efficiency has been developed to detect spontaneous and induced 6-thioguanine-resistant T-lymphocytes (HPRT mutants) from the spleen of adult mice. The mean cloning efficiency in untreated male mice of 20-22 weeks old was 34.5 +/- 11.2% (SD) and the corresponding mutant frequency 0.7 +/- 0.8 (SD) x 10(-6). The cloning efficiencies obtained in this study are substantially higher than those reported previously by other investigators. Using this assay, it could be demonstrated that inhalation exposure of mice to 200, 500 or 1300 ppm of 1,3-butadiene for 6 h/day on 5 consecutive days caused a statistically significant induction of 6-thioguanine-resistant mutations in T-lymphocytes from spleens of adult mice exposed to 1300 ppm. The exposure to 1300 ppm resulted in a three-fold increase of the spontaneous mutant frequency. The mutant frequency after exposure to 500 ppm was higher than the control but the increase was not significant.
authors.affiliation: MGC-Department of Radiation Genetics and Chemical Mutagenesis, Sylvius Laboratory, State University of Leiden, The Netherlands.
authors.forename: A D
authors.initials: AD
authors.lastname: Tates
authors.forename: F J
authors.initials: FJ
authors.lastname: van Dam
authors.forename: F A
authors.initials: FA
authors.lastname: de Zwart
authors.forename: C M
authors.initials: CM
authors.lastname: van Teylingen
authors.forename: A T
authors.initials: AT
authors.lastname: Natarajan
mesh_terms: D000280:Administration, Inhalation; D000818:Animals; D002070:Butadienes / Q000008:administration & dosage / Q000633:toxicity*; D002999:Clone Cells; D046508:Culture Techniques / Q000379:methods; D004305:Dose-Response Relationship, Drug; D004351:Drug Resistance; D007041:Hypoxanthine Phosphoribosyltransferase / Q000235:genetics; D008297:Male; D051379:Mice; D008809:Mice, Inbred C3H; D008815:Mice, Inbred Strains; D009152:Mutagenicity Tests; D009153:Mutagens / Q000633:toxicity*; D012044:Regression Analysis; D013154:Spleen / Q000166:cytology / Q000187:drug effects* / Q000473:pathology; D013601:T-Lymphocytes / Q000166:cytology / Q000187:drug effects*; D013866:Thioguanine / Q000633:toxicity*
chemical_list: D002070:Butadienes; D009153:Mutagens; D007041:Hypoxanthine Phosphoribosyltransferase; D013866:Thioguanine; C031763:1,3-butadiene