Mutagenicity of 1,3-butadiene at the Hprt locus of T-lymphocytes following inhalation exposures of female mice and rats
| Autor: | Vernon E Walker, Quanxin Meng, Andrew A. Reilly, Tao Chen, Dale M. Walker, Robert H. Heflich, Rogene F. Henderson, Michael J Bauer |
|---|---|
| Rok vydání: | 1999 |
| Předmět: |
Hypoxanthine Phosphoribosyltransferase
DNA Complementary Time Factors Ratón T-Lymphocytes Health Toxicology and Mutagenesis Lymphocyte DNA Mutational Analysis Mutant Spleen Biology medicine.disease_cause Mice Species Specificity Administration Inhalation Butadienes Genetics medicine Animals Molecular Biology Carcinogen Mutation Dose-Response Relationship Drug Mutagenicity Tests Molecular biology Rats Inbred F344 Clone Cells Rats medicine.anatomical_structure Hypoxanthine-guanine phosphoribosyltransferase Toxicity Female Mutagens |
| Zdroj: | Mutation Research/Fundamental and Molecular Mechanisms of Mutagenesis. 429:107-125 |
| ISSN: | 0027-5107 |
| DOI: | 10.1016/s0027-5107(99)00104-9 |
| Popis: | The species specific response to 1,3-butadiene (BD), an important industrial chemical, was investigated by determining the influence of exposure duration and exposure concentration on the mutagenicity of BD in mice and rats and by defining the spectra of mutations in the Hprt gene T-cell mutants from control and BD-exposed mice. Female B6C3F1 mice and F344 rats (4–5 weeks old) were exposed by inhalation to 0, 20, 62.5, or 625 ppm of BD for up to 4 weeks (6 h/day, 5 days/week). Groups of control and exposed animals ( n =4–12/group) were necropsied at multiple time points after exposure and the T-cell cloning assay was used to measure Hprt mutant frequencies in lymphocytes isolated from spleen. Mutant clones collected from control and BD-exposed mice were propagated and analyzed by RT–PCR to produce Hprt cDNA for sequencing. In animals necropsied 4 weeks after 2 or 4 weeks of BD exposure (0 or 625 ppm), the rate of accumulation of mutations was greater in mice than in rats. Supra-linear dose–response curves were observed in BD-exposed mice, indicating a higher efficiency of mutant induction at lower concentrations of BD. The mutagenic potency estimates (represented by the differences in the areas under the mutant T-cell `manifestation' curves of treated vs. control animals) in mice were 11 and 61 following 4 weeks of exposures to 62.5 and 625 ppm of BD, respectively, while mutant frequencies (M f s) in rats were significantly increased only at 625 ppm BD (mutagenic potency of 7). Molecular analysis of Hprt cDNA from expanded T-cell clones from control and BD-exposed mice demonstrated an increased frequency of mutants in exposed animals that likely contain large deletions in the Hprt gene ( P =0.016). These data indicate that both exposure duration and exposure concentration are important in determining the magnitude of mutagenic response to BD, and that mutagenic and carcinogenic properties of BD in mice may be related more to the ability of its metabolites to cause chromosomal deletions than to produce point mutations. |
| Databáze: | OpenAIRE |
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