Tolerance of spermatozoa to hypotonic stress: role of membrane fluidity and correlation with cryosurvival.
Reprod Fertil Dev
; 27(2): 285-93, 2015 Jan.
Article
em En
| MEDLINE
| ID: mdl-25482034
ABSTRACT
The aim of this study was to evaluate inter-individual variability in osmotic properties of stallion spermatozoa and its correlation with cryosurvival. In addition, temperature dependency of hypo-osmotic tolerance and membrane fluidity were studied. Stallion sperm membranes exhibited good resistance towards hypotonic stress in the 15-30 °C temperature range, whereas membrane stability was found to be decreased at 4 and 37 °C. Bull spermatozoa showed greater hypo-osmotic tolerance compared with stallion spermatozoa, especially at temperatures above 30 °C, which coincided with decreased membrane fluidity of bovine spermatozoa in this temperature range. The critical osmolality at 22 °C, at which half of the sperm population survived exposure to hypotonic saline solution, was found to vary between 55 and 170 mOsm kg(-1) among different stallions. Clear correlations were found for pre- versus post-freeze sperm motility and membrane integrity. Pre-freeze percentages of membrane-intact spermatozoa after exposure to hypotonic stress showed a weak correlation with sperm motility after cryopreservation. This correlation, however, was not found when data were corrected for initial numbers of membrane-intact spermatozoa in the sample. We thus conclude that studies on pre-freeze tolerance towards hypotonic stress cannot be used to predict sperm cryosurvival rates for individual stallions.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Pressão Osmótica
/
Espermatozoides
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Criopreservação
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Membrana Celular
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Sobrevivência Celular
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Cavalos
Limite:
Animals
País/Região como assunto:
Europa
Idioma:
En
Ano de publicação:
2015
Tipo de documento:
Article