Abstract:

Objective To investigate the effects of acrylamide (AA) on reproductive toxicity and expression of proliferating cell nuclear antigen (PCNA) in male rats. Methods Forty male SD rats were randomly divided into control group (double distilled water), 4 mg/kg AA treatment group, 12 mg/kg AA treatment group and 36 mg/kg AA treatment group. Thirty days after intragastric administration, testes of rats were obtained, and the histological changes of testicular tissues were observed with HE staining. The apoptosis of testicular cells was detected by TUNEL assay. The serum concentrations of testosterone and estradiol were measured by chemiluminescent method. The expression of PCNA mRNA in testicular tissues was determined by RT-PCR, and the expression of PCNA protein in testicular tissues was examined by immunohistochemistry and Western blotting. Results The body weight of rats in 12 mg/kg AA treatment group or 36 mg/kg AA treatment group was significantly lower than that in control group (P<0.05). For 12 mg/kg AA treatment group and 36 mg/kg AA treatment group, the numbers of spermatogenic cells in testicular tissues were smaller, and there were atrophy of spermatogenic epithelia, vacuoles in lumina, and increased numbers of apoptotic cells. The serum concentration of testosterone in each treatment group was significantly lower than that in control group (P<0.05), and the serum concentrations of estradiol in 12 mg/kg AA treatment group and 36 mg/kg AA treatment group were significantly lower than that in control group (P<0.05). The expression of PCNA mRNA and protein in testicular tissues in 12 mg/kg AA treatment group and 36 mg/kg AA treatment group was significantly lower than that in control group (P<0.05). Conclusion Exposure to AA may result in the decrease of sex hormone secretion, pathological changes of testicular tissues, increase of apoptotic cells and decrease of expression of PCNA protein, which may interrupt the balance between proliferation and apoptosis of spermatogenic cells and lead to the functional impairment of reproductive system.

Key words: acrylamide, proliferating cell nuclear antigen, apoptosis, testosterone, estradiol