Efeito da adição de caseinato de sódio sobre a viabilidade do sêmen bubalino criopreservado
Data
2019-09-13
Autores
Silva, Fernando Evaristo da
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
O uso do sêmen refrigerado proporciona maiores taxas de prenhez se comparado ao do sêmen congelado. Essa diferença parece estar relacionada às lesões mais severas das membranas espermáticas desencadeadas pelo processo de congelação. Por sua habilidade de se ligar às proteínas ligadoras de espermatozoides e ao íon cálcio, o caseinato de sódio vem sendo estudado como uma substância capaz de inibir a capacitação espermática precoce, uma importante causa de diminuição da taxa de prenhez quando do uso de sêmen congelado. O primeiro objetivo deste estudo foi avaliar a possibilidade de um diluente comercial a base de gema de ovo, destinado à congelação de sêmen bovino, ser empregado para a criopreservação de sêmen bubalino; o segundo objetivo foi investigar o efeito do uso desse diluente, suplementado com caseinato de sódio, na criopreservação de espermatozoides bubalinos, por meio da avaliação dos espermatozoides, por citometria de fluxo, e da cinética espermática, empregando-se o sistema CASA. Na primeira parte do estudo, quando comparados os resultados das avaliações da cinética espermática e integridade das membranas plasmática e acrossomal, observou-se que o processo de congelação seminal promoveu mais danos celulares que o processo de refrigeração. Na segunda parte do estudo, não foram observados efeitos da adição do caseinato de sódio ao diluente a base de gema de ovo. A partir dos resultados do presente estudo foi possível concluir que o diluente a base de gema de ovo testado foi adequado para a criopreservação de sêmen bubalino e que a adição do caseinato de sódio não diminuiu os efeitos deletérios relacionados à criopreservação seminal.
The use of cooled semen results in higher pregnancy rates compared than the use of frozen semen. This result seems to be related to the more severe damages triggered by the freezing process, when compared to those observed during the refrigeration. Due to its ability to bind to sperm-binding proteins and calcium ions, sodium caseinate has been studied as a ubstance capable to prevent early sperm capacitation, a major cause of decreased pregnancy rate after using frozen semen. The first objective of this study was to evaluate if a commercial egg yolk diluent developed for freezing bovine semen could be used for buffalo semen cryopreservation; the second objective was to investigate the effect of this diluent, added with sodium caseinate, during the procedures of buffalo sperm cryopreservation, using flow cytometry and computer-assisted sperm analysis. In the first part of the study, comparing the results of spermatic kinetics and plasma and acrosomal membranes integrity, it was observed that the freezing process resulted in more cell damage than the cooling process. In the second part of the study, no effects of the addition of sodium caseinate to the egg yolk diluent were observed. From the results of the present study it was possible to conclude that the egg yolk-based diluent was suitable for buffalo semen cryopreservation and that the addition of sodium caseinate did not decrease the deleterious effects related to seminal cryopreservation.
The use of cooled semen results in higher pregnancy rates compared than the use of frozen semen. This result seems to be related to the more severe damages triggered by the freezing process, when compared to those observed during the refrigeration. Due to its ability to bind to sperm-binding proteins and calcium ions, sodium caseinate has been studied as a ubstance capable to prevent early sperm capacitation, a major cause of decreased pregnancy rate after using frozen semen. The first objective of this study was to evaluate if a commercial egg yolk diluent developed for freezing bovine semen could be used for buffalo semen cryopreservation; the second objective was to investigate the effect of this diluent, added with sodium caseinate, during the procedures of buffalo sperm cryopreservation, using flow cytometry and computer-assisted sperm analysis. In the first part of the study, comparing the results of spermatic kinetics and plasma and acrosomal membranes integrity, it was observed that the freezing process resulted in more cell damage than the cooling process. In the second part of the study, no effects of the addition of sodium caseinate to the egg yolk diluent were observed. From the results of the present study it was possible to conclude that the egg yolk-based diluent was suitable for buffalo semen cryopreservation and that the addition of sodium caseinate did not decrease the deleterious effects related to seminal cryopreservation.
Descrição
Palavras-chave
Búfalo, Espermatozoide, BSP, Caseína, Criopreservação, Buffalo, Sperm, , Casein, Criopreservation