Keywords: 
• chlorpyrifos /
• reactive oxygen species /
• glutathione /
• DNA-protein crosslinks /
• reproductive toxicity

Abstract: To research the effect of reproductive toxicity of chlorpyrifos on male mice which were gavage with different concerntrations of chlorpyrifos. Male mice were orally administrated with chlorpyrifos daily for 7 days at the concentrations of 3, 6 and 12 mg·kg^-1, respectively. Afterwards, the contents of ROS (reactive oxygen species) and GSH (glutathione) in the testis tissue homogenates, and DPC (DNA-protein crosslink) coefficients in the testis cells were measured. Testis tissue sections were made then stained for pathological observations under microscope. Results showed that the contents of ROS and DPC coefficients gradually increased in a dose-dependent manner, whereas GSH content decreased. In the exposure group, with the dose of 6 mg kg^-1, GSH content was significantly higher than that of the control group (p < 0.05); ROS contents had extremely significant differences (p < 0.01). Stained sections presented the increased cavity surface in the testicular seminiferous tubules. Sperm and sperm generation associated cells were obviously reduced. In the higher dose groups (12 mg·kg^-1), the differences of DPC, ROS, and GSH were all significant (p < 0.01). Within the testicular seminiferous tubules, elongations of sperm cells were blocked; mature sperms were hardly found; spermatogenic cells apoptosis and stromal cell proliferation were observed. It can be concluded that chlorpyrifos at higher doses(≥ 6 mg·kg^-1) can increase the oxidative stress and pathological damagein male mouse testis, which induced the reproductive toxicity.