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.

Is stallion epididymal fluid phosphoproteome affected by the equine reproductive season?

Phosphorylation and dephosphorylation of proteins are considered to be the most important processes in sperm maturation during epididymal transit. The main aim of this study was to isolate and identify phosphoproteins from the epididymal milieu obtained from reproductively mature stallions during and out of the breeding season. With the use of 1D-PAGE and nanoLC-MS/MS, we identified phosphoproteins that fulfil various functions: regulatory, transport, motility, ubiquitination, chaperone, antioxidant, apoptotic and enzymatic. Moreover, we characterized tyrosine, serine and threonine phosphorylation patterns, taking into consideration the seasonal and epididymal segment variables. The intensity of phosphorylation and profiles of phosphoproteins varied in subsequent regions of the epididymis. With the use of western and immunoblot tests, we demonstrated that fourteen proteins underwent phosphorylation both during and out of the breeding season. However, significant differences (p≤0.05) in the phosphorylation status were demonstrated in the case of 44 kDa (glutamine synthetase), 38 kDa (malate dehydrogenase), 34 kDa (clusterin/inorganic pyrophosphatase), 31 kDa (clusterin/ /ubiquitin thioesterase), 29 kDa (14-3-3 protein/purine nucleotide phosphorylase) for the season factor and 55 (Rab GDP dissociation inhibitor alpha) and 31 kDa ((clusterin/ubiquitin thioesterase) proteins for the segment factor. The occurrence of the other phosphoproteins was spontaneous among individuals and in both seasons.

Relation between nitric oxide (NO) level in semen and certain properties of boar spermatozoa stored at 17°C

The aim of this study was to measure the NO level in boar semen held in a liquid state and to determine its putative relation to spermatozoa motility, plasma membrane integrity, mitochondrial membrane potential and ATP content. Generally, the percentage of spermatozoa which generated nitric oxide gradually increased, while NO level in the surrounding medium declined during the liquid preservation. NO generation in semen preserved in BTS was higher as compared to those in Androhep®Plus. We demonstrated the positive correlation between the NO level in fresh spermatozoa and their quality. We also showed negative correlation between nitric oxide level in spermatozoa preserved in BTS and sperm cells motility as well as plasma membrane integrity. Results obtained in this study confirm that NO may affect sperm physiology in a dualistic manner.