Nitric oxide production by spermatozoa and sperm characteristics in dogs with benign prostatic hyperplasia.

The aim of this study was to evaluate the effect of benign prostatic hyperplasia (BPH) on nitric oxide (NO) production by spermatozoa and sperm parameters in dogs. The study was conducted on 40 intact dogs of various breeds. The dogs were assigned to two groups: BPH group (n=20) and non-affected group (n=20). The sperm concentration and motility parameters of spermatozoa were assessed using computer-assisted sperm analysis. For the assessment of sperm morphology monochromatic Diff-Quick stain was used. Plasma membrane integrity, mitochondrial membrane potential and the spermatozoa producing nitric oxide and with apoptotic-like changes were determined using fluorescent stain methods. The percentages of motile sperm, sperm with progressive motility and normal sperm were statistically significantly (p<0.05) lower in dogs with BPH than in non-affected dogs. The proportion of sperm in motility subcategory RAPID was statistically significantly (p<0.05) lower in dogs with BPH than in control dogs, whereas in the STATIC motility subcategory the proportion was significantly (p<0.05) higher in dogs with BPH. The percentage of spermatozoa producing NO was significantly (p<0.05) higher in dogs with BPH than in control dogs. In conclusion, the results of this study showed that BPH adversely affects semen quality, especially motility, in dogs. The decreased semen quality was associated with an increased proportion of spermatozoa generating NO. Further research is needed to clarify the mechanisms by which BPH affects semen quality.