Endocrine Abstracts

Nonylphenol (NP) is an endocrine disruptor that is capable of interfering with the hormonal system of numerous organisms. Estrogens play a central role in female reproduction, but also affect the male reproductive system. In males, they stimulate sperm capacitation, acrosome reaction and fertilizing ability. The aim of the present study was to investigate the effect of 4-nonylphenol (4-NP) and the effect of 17β-estradiol (E₂) on bovine spermatozoa motility. We examined the dose- and time-dependent effect of 4-NP (1, 10, 100 and 200 μg/ml) with and without addition 1 μg/ml E₂ on the spermatozoa motility during several time periods (0, 2, 4 and 6 h). The spermatozoa motility was determined by Computer Assisted Semen Analyzer (CASA) system using the Sperm Vision program and the percentage of motile spermatozoa (motility >5 μm/s) was evaluated. This study was performed in 10 replicates at each concentration. At least 1000 spermatozoa were analyzed in each sample. The control group (medium without NP) was compared to the experimental groups (exposed to different concentrations of NP), to the positive control group (medium with E₂) and to the experimental groups (exposed to different concentrations of NP with addition E₂). The obtained data showed a decreased motility of bovine spermatozoa in all experimental groups with the addition of 4-NP. NP significantly (P<0.001 and P<0.05) decreased spermatozoa motility in all experimental groups. The lowest spermatozoa motility (P<0.001) was found at doses >100 μg/ml of NP in comparison with the control group during all time periods. The addition of 17β-estradiol significantly (P<0.05) increased the motility in the experimental groups with 10, 100 and 200 μg/ml of NP during 4 and 6 h of cultivation. In conclusion, our results confirm that the high doses of 4-NP have the negative effect on spermatozoa motility, but E₂ can have the stimulating effect on spermatozoa motility.

4-nonylphenol, 17β-estradiol, bovine spermatozoa, motility, CASA system.

Declaration of funding: This work was supported by the Scientific Agency of the Slovak Republic VEGA No. 1/0532/11.