MICRONUCLEUS INDUCTION IN GERM AND SOMATIC-CELLS OF THE MOUSE AFTER EXPOSURE TO THE BUTADIENE METABOLITES DIEPOXYBUTANE AND EPOXYBUTENE

The genotoxicity of diepoxibutane (DEB) and epoxybutene (EB), two of t he main metabolites of 1,3-butadiene, was tested in the germ and somat ic cells of the mouse by applying an WIN assay in early spermatids, an d in peripheral blood reticulocytes of a subgroup of the same animals. DEB (0.17 and 0.35 mmol/kg) and EB (0.35, 0.70 and 1.04 mmol/kg) were administered i.p. In the germ cell assay, significant increases of MN were observed after treatment of premeiotic S-phase cells with both b utadiene metabolites, but DEB was shown to be more powerful than EB in the induction of chromosomal damage. A weak effect of the same compou nds was also found after treatment of late spermatocytes, approaching the meiotic divisions. From the MN assay in peripheral blood reticuloc ytes, a statistically significant increase of the frequency of MN was detected at each dose tested for both chemicals. However, the results have again shown that DEB is much more efficient than EB in inducing c hromosome damage.