An official journal of the Society for Biology of Reproduction and the Institute of Animal Reproduction and Food Research of Polish Academy of Sciences in Olsztyn
Elsevier

March 2013 (No. 1)

Supplementation of the thawing medium with reduced glutathione improves function of frozen-thawed goat spermatozoa

Joaquín Gadea *, David Gumbao, Belén Gómez-Giménez, Juan Carlos Gardón

Physiology of Reproduction Group, Departamento de Fisiología, Universidad de Murcia, Campus Mare Nostrum, Murcia, Spain

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Abstract
Sperm cryopreservation represents a useful tool in the management of reproduction in goat production. However, freezing and thawing produce physical and chemical stress on the sperm membrane that reduces their viability and fertilizing ability. In this study, firstly we evaluated the effects of reduced glutathione (GSH, 1 and 5 mM) supplementation of the thawing extender on parameters of frozen-thawed goat spermatozoa. We used a set of functional sperm tests that included sperm motility assayed by computer assisted semen analysis (CASA), membrane lipid packing disorder, spontaneous acrosome reaction, free radical production (ROS generation) and sperm chromatin condensation. The main findings from this study were that addition of GSH to the thawing medium resulted in: (1) a higher motility and progressive motility; (2) a higher number of non-capacitated viable spermatozoa; (3) higher number of viable spermatozoa with intact acrosome; (4) a reduction in ROS generation and (5) lower chromatin condensation. In a second study, the additions of reduced (GSH, 5 mM) or oxidized glutathione (GSSG, 2.5 mM) to the thawing media were evaluated. We confirmed the protective effect of GSH on the sperm functionality. The addition of GSSG to the thawing media was less protective to sperm functions compared to GSH. Addition of GSH to the thawing extender could be of significant benefit in improving the function and fertilizing capacity of frozen goat spermatozoa. The information derived from this study suggests the importance of oxidative stress as responsible for cryo-injury to spermatozoa and opens new windows to explore the practical application of antioxidants to improve the quality of post-thaw
goat semen.

Reproductive Biology 2013 13 1: 24–33.

* Corresponding author: Department of  Physiology, Facultad de Veterinaria, Universidad de Murcia, 30100 Murcia, Spain; E-mail address: jgadea@um.es