Objective: To investigate the effects of exposure to atrazine on meiosis and spermatogenesis in adult male mice.
Methods: We divided 16 adult male Institute for Cancer Research (ICR) mice into a solvent control and an atrazine exposure group of an equal number and intraperitoneally injected with solvent dimethylsulfoxide (DMSO) and atrazine at 100 mg/kg/d, respectively. After 4 weeks of treatment, we obtained the body and testis weights of the mice, observed the changes in the testicular histomorphology, examined the cell apoptosis in the testis tissue, and determined the expressions of meiosis-related key genes in the spermatocytes by real-time fluorescence quantitative PCR.
Results: Compared with the controls, the mice treated with atrazine showed significantly less increase in the body weight (［11.2 ± 0.17］ vs ［8.29 ± 0.51］ g, P < 0.05) and testis weight (［0.28 ± 0.01］ vs ［0.24 ± 0.01］ g, P < 0.05), loosely arranged and thinned lumens of seminiferous tubules, disordered arrangement and reduced number of spermatogenic cells, decreased sperm concentration (［2.36 ± 0.14］ vs ［0.90 ± 0.12］ ×10⁶/ml, P < 0.01) and increased percentage of morphologically abnormal sperm in the epididymis tail (［8.60 ± 1.07］% vs ［18.02 ± 1.71］%, P < 0.05), elevated apoptosis rate of spermatocytes, and down-regulated the expressions of SCP1, SCP3 and Rad51 mRNA in the spermatocytes (P < 0.05).
Conclusions: Atrazine can reduce spermatogenesis in male mice by damaging testicular morphology, increasing the apoptosis of spermatocytes and down-regulating the expressions of meiosis-related genes in the spermatocytes.
Keywords: male mouse; meiosis; spermatogenesis; atrazine.