Criopreservação e fertilidade de espermatozoides do ejaculado e recuperados da cauda do epidídimo de garanhões subférteis

• Ano de defesa: 2013
• Autor(a) principal: Monteiro, Gabriel Augusto [UNESP]
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Estadual Paulista (Unesp)
• Palavras-chave em Português: Criopreservação; Preservação do sêmen; Reprodução animal; Equino - Reprodução; Cryopreservation
• Link de acesso: http://hdl.handle.net/11449/108399

Despite the benefits provided by seminal plasma during natural cover when biotechnology are used as artificial insemination, its function is questionable, since studies using spermatozoa from cauda epididymis with or without the addition of seminal plasma showed no difference in conception rates. Furthermore, studies have reported deleterious effects of secretions from accessory glands on sperm viability and conception rate, especially in stallions with poor semen quality. Thus the aims of this study were: 1) compare the kinetic parameters, structural viability and fertility of sperm recovered from ejaculate and cauda epididymis of subfertile stallions. 2) evaluate differences in electrolyte composition in the seminal plasma of animals with high and low fertility. 3) compare the effect of seminal plasma addition from stallions with high and low fertility on freezability and viability of sperm from the ejaculate and cauda epididymis of subfertile stallions. The assessment of each samples was determined by computer-assisted sperm analyses of motility (CASA, Thorne Research - HTM IVOS) and flow cytometry analyses of plasma membrane integrity, acrosome integrity, peroxidation of sperm membranes, DNA fragmentation index, degree of protein tyrosine phosphorylation in sperm surface and caspase activity. The epididymal sperm after thawing showed superiority in kinetic parameters and sperm viability, as well as better fertility, demonstrating that these spermatozoa are more resistant to freezing process when compared to sperm from the ejaculate. The seminal plasma of subfertile stallions has higher sodium concentrations in the seminal plasma than fertile stallions, what makes this finding a possible way to explain the deleterious effect of seminal plasma in these animals. Moreover, it was found that this deleterious effect is dose-dependent since the addition of 20% of seminal plasma from fertile and ...