Induction of micronuclei by vinyl acetate in mouse bone marrow cells and cultured human lymphocytes

Abstract A dose-dependent increase in micronucleated polychromatic erythrocytes was observed in the bone marrow of male C57B1/6 mice 30 h after a single intraperitoneal injection of vinyl acetate (250, 500, 1000 or 2000 mg/kg b.wt.; (9–14 animals per group). The effect was statistically significant at 1000 mg/kg (1.33±0.29 vs. 0.6±0.0% in olive oil-treated controls) and at 2000 mg/kg (1.57±0.19%) of vinyl acetate. These doses were fatal to 6 (100 mg/kg) and 8 (2000 mg/kg) out of 14 animals in both groups. The ratio of polychromatic to normochromatic cells decreased as a function of vinyl acetate dose. Cyclophosphamide (20 mg/kg), used as a positive control chemical, induced a clear increase in micronucleated polychromatic erythrocytes (2.07±0.20%). None of the treatments affected the number of micronuclei in normochromatic erythrocytes. In human whole-blood lymphocyte cultures, micronucleus induction by a 48-h treatment with vinyl acetate (0.125, 0.25, 0.5, 1 and mM; 24 h after culture initiation) was studied in lymphocytes with preserved cytoplasm from smear prepared by a method involving the removal of erythrocytes at harvest by sodium cyanide treatment to improve preparation quality. The frequency of micronucleated lymptocytes reached a peak at 0.5 mM (3.2±1.0% vs. 0.9±0.1% in control cultures) and 1 mM (3.1±0.7%), with a decline at 2 mM probably because of a toxic effect resulting in mitotic inhibition.