Effect of non-sperm cells removal with single-layer colloidal centrifugation on myeloperoxidase concentration in post-thaw equine semen.

This research examines the impact of removing non-sperm cells with single-layer colloidal centrifugation on myeloperoxidase concentration in frozen equine semen. The study found that this process decreases non-sperm cells and myeloperoxidase concentrations, both of which are associated with decreased sperm movement.

Study Objective and Design

• The focus of this study was to assess the impact of a single-layer colloidal centrifugation, carried out prior to freezing, on the concentration of non-sperm cells (NSC) and myeloperoxidase (MPO) in equine semen.
• The experimental model involved freezing semen samples while comparing it to the samples that had undergone prior centrifugation with two different levels of a single-layer colloid medium.

Myeloperoxidase (MPO) and Non-Sperm Cells (NSC)

• MPO is a pro-oxidant enzyme that neutrophils contain and release during degranulation or after breaking down. MPO present in frozen-thawed semen is linked to declined sperm motility.
• Recently, researchers have highlighted the link between MPO concentration in post-freeze semen and the presence of NSC.
• NSC were primarily made up of epithelial cells or cellular debris as presented by MPO immunocytochemistry.

Findings and Conclusions

• The process of single-layer colloid centrifugation resulted in a decrease in the concentrations of NSC and MPO in frozen-thawed semen.
• The study found a correlation between the concentration of NSC and MPO in the supernatant’s upper layer.
• NSC release MPO during the freezing process, as shown by MPO immunocytochemistry.
• The MPO immunostaining was predominantly identified on NSCs across all stages of processing and cryopreservation of semen.

In sum, this study indicates that removing NSCs from fresh equine semen prior to freezing can help improve sperm motility.