Effect of MnTBAP on in vitro capacitation of frozen-thawed stallion sperm.

The research focuses on how an antioxidant compound, MnTBAP, impacts the in vitro capacitation of thawed stallion sperm. The study’s findings show that MnTBAP supplementation positively affects key sperm viability markers, potentially improving sperm sample quality held under in vitro conditions.

Introduction to Study

• The research investigates the impact of MnTBAP, a compound with antioxidant properties, on in vitro capacitation of stallion sperm after freeze-thawing. Sperms manipulated in vitro often experience structural and functional changes, majorly due to oxidative stress. The supplementation of antioxidants provides a possible solution to preserving sperm quality during in vitro handling.

Methodology

• For the experiment, stallion spermatozoa were incubated in a special sperm-TLP base medium for 4 hours. The conditions for the incubation were divided into: non-capacitating, capacitating, and capacitating plus addition of 150 mM MnTBAP.
• The incubation was carried out at 37.5 °C in a humidified air atmosphere. The samples were examined immediately after thawing and at the end of the incubation period.
• Several variables were assessed relating to the sperm, such as plasma membrane integrity, acrosome integrity, intracellular calcium concentrations, intracellular pH, ATP concentrations, motility, and a heterologous zona-binding assay.
• Techniques used for analysis included flow cytometry, fluorescent microscopy and chemiluminescence.

Results and Findings

• Results demonstrated that capacitation-like changes were synergistically induced by cAMP agonists, a phosphodiesterase inhibitor and bicarbonate. This indicated that these elements can cause changes in sperm similar to those seen in natural capacitation.
• The presence of bovine serum albumin seemed to negatively affect the plasma membrane of the sperm.
• The addition of MnTBAP had a positive impact on several markers related to viability, including plasma membrane integrity, membrane fluidity, and the associated intracellular pH, especially under capacitating conditions.

Conclusion

• The study concluded that the antioxidant activity of MnTBAP ended up enhancing the in vitro incubation conditions for frozen-thawed stallion sperm, suggesting it could be a useful strategy for preserving sperm quality during in vitro processing.