Effects of P-nitrophenol exposure on the testicular development and semen quality of roosters.

The widespread use of P-nitrophenol (PNP) as a raw material in pesticides, medicines and dyes has led to environmental pollution. PNP is a well-known endocrine disruptor in mammals and quails. This study investigated the effects of long-term PNP exposure on the testicular development and semen quality of roosters. Pubescent and postpubescent animals were given drinking water supplemented with (0 mg/L, 1 mg/L, 10 mg/L, or 100 mg/L) PNP for eight weeks or sixteen weeks. The relative testis weight, antioxidant index, serum hormone concentration, morphological changes, semen quality and expression of major steroidogenic genes were measured. The results showed that eight weeks of PNP exposure decreased CAT activity and increased H2O2 level in serum and testes in the 10 mg/L and 100 mg/L PNP-treated groups. Detached sperm cells were also found in the testicular tissues of the 100 mg/L PNP-treated group. After sixteen weeks of PNP exposure, daily weight gain, sperm motility, serum testosterone concentration and 3ß1-hydroxysteroid dehydrogenase (HSD3ß1) mRNA expression were decreased in the 100 mg/L PNP-treated group. Some vacuoles in the seminiferous epithelium in the testicular tissues were found in the 10 mg/L and 100 mg/L PNP-treated groups. In conclusion, as an endocrine disruptor, PNP exposure impaired antioxidant capacity, reduced testosterone synthesis, caused morphological changes in testes, and ultimately decreased semen quality in the roosters. The reproductive damage of PNP to roosters depended on the length of exposure time and the administered dose.