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- Ortega Ferrusola, C., et al.
(författare)
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Stallion spermatozoa surviving freezing and thawing experience membrane depolarization and increased intracellular Na
- 2017
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Ingår i: Andrology. - : WILEY. - 2047-2919 .- 2047-2927. ; 5:6, s. 1174-1182
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Tidskriftsartikel (refereegranskat)abstract
- In order to gain insight of the modifications that freezing and thawing cause to the surviving population of spermatozoa, changes in the potential of the plasma membrane (Em) and intracellular Na+ content of stallion spermatozoa were investigated using flow cytometry. Moreover, caspase 3 activity was also investigated and the functionality of the Na+-K+ ATPase pump was investigated before and after freezing and thawing. Cryopreservation caused a significant (pamp;lt;0.001) increase in the subpopulation of spermatozoa with depolarized sperm membranes, concomitantly with an increase (pamp;lt;0.05) in intracellular Na+. These changes occurred in relation to activation of caspase 3 (pamp;lt;0.001). Cryopreservation reduced the activity of the Na-K+ pump and inhibition of the Na+-K+ ATPase pump with ouabain-induced caspase 3 activation. It is concluded that inactivation of Na+-K+ ATPase occurs during cryopreservation, an inhibition that could play a role explaining the accelerated senescence of the surviving population of spermatozoa.
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| 2. |
- Ortiz-Rodriguez, Jose Manuel, et al.
(författare)
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The incorporation of cystine by the soluble carrier family 7 member 11 (SLC7A11) is a component of the redox regulatory mechanism in stallion spermatozoa
- 2019
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Ingår i: Biology of Reproduction. - : OXFORD UNIV PRESS INC. - 0006-3363 .- 1529-7268. ; 101:1, s. 208-222
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Tidskriftsartikel (refereegranskat)abstract
- Oxidative stress is considered amajor mechanism causing sperm damage during cryopreservation and storage, and underlies male factor infertility. Currently, oxidative stress is no longer believed to be caused only by the overproduction of reactive oxygen species, but rather by the deregulation of redox signaling and control mechanisms. With this concept in mind, here, we describe for the first time the presence of the soluble carrier family 7 member 11 (SLC7A11) antiporter, which exchanges extracellular cystine (Cyss) for intracellular glutamate, in stallion spermatozoa, as well as its impact on sperm function using the specific inhibitor sulfasalazine. Spermatozoa incubated with Cyss exhibited an increased intracellular GSH content compared with controls (P amp;lt; 0.01): 50% in fresh extended stallion spermatozoa and 30% in frozen-thawed spermatozoa. This effect was prevented by the addition of sulfasalazine to the media. Cystine supplementation also reduced the oxidation-reduction potential of spermatozoa, with sulfasalazine only preventing this effect on fresh spermatozoa that were incubated for 3 h at 37 degrees C, but not in frozen-thawed spermatozoa. While sulfasalazine reduced the motility of frozen-thawed spermatozoa, it increased motility in fresh samples. The present findings provide new and relevant data on the mechanism regulating the redox status of spermatozoa and suggest that a different redox regulatory mechanism exists in cryopreserved spermatozoa, thus providing new clues to improve current cryopreservation technologies and treat male factor infertility. Summary Sentence The SLC7A11 antiporter that exchanges cystine by intracellular glutamate is present and functional in stallion spermatozoa, but cryopreserved spermatozoa may present altered functionality.
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