Objective       To determine the toxic effects of 1

2

3

4-diepoxybutane (DEB)

a metabolic intermediates of 1

3-butadiene

on germ cells of male mice.       Methods       Male Kunming mice were randomly divided into 3 groups

including solvent control group (PBS)

DEB low dose (17 mg/kg) exposure group and high dose (42.5 mg/kg) exposure group. Each mouse was intraperitoneally treated for 3 times at an interval of 48 h. The mice were sacrificed on day 21 after the first injection. The testis coefficient

sperm density

sperm motility and pathological changes of the testis tissue were examined. The cell cycle distribution and DNA content of testicular cells were analyzed by flow cytometry. The quantity of malodialdehyde (MDA) and the activity of glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD) in liver were detected by chemical colorimetry.       Results      Compared with control group

the testis coefficient and sperm density were decreased in DEB-treated groups

with 42.5 mg/kg DEB group reduced more significantly (P0.05). And the sperm percentage of the extremely slow or motionless was obviously increased (P0.05 or P0.01) in groups treated with low or high dose of DEB. Flow cytometry showed that the percentages of haploid and diploid cells were significantly lower in 42.5 mg/kg group than control group (P0.05)

whereas the percentages of tetraploid cells and G

2

/M cells were significantly higher than control (P0.05). Furthermore

with the increase of DEB treatment

the impaired testicular structure was observed. When compared with control group

the level of MDA was higher (P0.05)

but the activities of GSH-Px and SOD were lower (P0.05) in the liver tissue of mice treated with 42.5 mg/kg DEB (P0.05).       Conclusion      DEB exerts reproductive toxic effects on sperm cells

induces disturbance of cell cycle progression of spermatogenic cells

and leads to the oxidative stress in mice.