Specific Activity of Superoxide Dismutase in Stallion Seminal Plasma Is Related to Sperm Cryotolerance.

Marion Papas,Jaime Catalán,Anna Bassols,Jordi Miró,Laura Arroyo,Marc Yeste,Beatriz Fernandez-Fuertes

doi:10.3390/antiox8110539

Marion Papas, Jaime Catalán + Show 5 more

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https://doi.org/10.3390/antiox8110539

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Abstract

While the removal of seminal plasma is a routine practice prior to equine sperm cryopreservation, this fluid contains the main source of antioxidant enzymes able to scavenge these reactive oxygen species. Therefore, stallion seminal plasma components may have an impact on ejaculate freezability. Against this background, this study was designed to investigate whether the activities of the main stallion seminal plasma antioxidant enzymes are related to sperm cryotolerance. With this purpose, 16 ejaculates were collected from 14 healthy stallions, and each ejaculate was split into two aliquots. The first one was used to evaluate the activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX), and glutathione reductase (GSR) in seminal plasma. The second aliquot was extended and then processed for cryopreservation. Sperm motility and viability were evaluated before and after cryopreservation, and ejaculates were classified as of good (GFE) or poor freezability (PFE) based on total motile and viable spermatozoa at post-thaw. We observed that, while the specific activities of CAT, GPX, and GSR were similar between GFE and PFE, that of SOD was significantly (p < 0.05) higher in GFE than in PFE. We can thus conclude that, in stallions, the specific activity of SOD in the seminal plasma of a given ejaculate might be related to its freezability.

Highlights

Cryopreserved stallion semen is widely used in the equine breeding industry
From the 16 ejaculates included in this study, 8 were classified as good freezability ejaculates (GFE) and the other 8 were classified as poor freezability ejaculates (PFE)
Semen quality parameters including viability and progressive and total motilities did not differ between both groups

Summary

Introduction

Does cryopreservation of stallion sperm facilitate their availability and transport, but it preserves the genetic material for an unlimited period [1]. Since the process of freezing and thawing exposes sperm to severe cold shock and osmotic stress, their survival and fertilizing ability can be greatly compromised [3]. For this reason, efforts have been made to improve stallion sperm cryopreservation over the last years, testing the use of different cryoprotectants, including glycerol [1]. Optimizing cryopreservation protocols is still needed, as there is room to increase the fertilizing ability of frozen–thawed stallion sperm

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