Comparação entre dois métodos de remoção de plasma seminal na criopreservação de sêmen de búfalos (Bubalus bubalis)
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Data
2016-03-04
Autores
Albuquerque, Rodrigo dos Santos [UNESP]
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Universidade Estadual Paulista (Unesp)
Resumo
A criopreservação provoca injúrias aos espermatozoides e necessita de métodos que minimizem esses danos. Embora seja bastante discutida, a remoção do plasma seminal tornou-se uma alternativa para melhorar a qualidade e viabilidade espermática após a congelação e vem sendo utilizada em outras espécies na tentativa de obter bons resultados. O objetivo deste estudo foi comparar a remoção do plasma seminal de bubalinos tanto por filtragem (SpermFilter®) quanto por centrifugação sobre a qualidade do sêmen descongelado de búfalos. Foram utilizados sete touros da raça Murrah, os quais foram submetidos à colheita de sêmen por vagina artificial uma vez por semana. Os ejaculados foram diluídos com Botu-Bov® e fracionados em alíquotas para confrontar três técnicas antes da congelação: grupo C (Criopreservação convencional com plasma seminal), grupo CE (Criopreservação removendo o plasma seminal por centrifugação) e grupo F (Criopreservação removendo o plasma seminal por filtragem). O sêmen fresco foi analisado quanto ao volume, aspecto, cor, concentração (câmara de Neubauer), turbilhonamento, motilidade progressiva, vigor e morfologia espermática. No sêmen descongelado, foram avaliados a cinética espermática pelo CASA, a integridade de membrana plasmática, acrossoma, potencial de membrana mitocondrial e quantificação de EROs por citometria de fluxo e, adicionalmente, foi estimado o grau de peroxidação lipídica pela técnica de TBARS. Os resultados revelam que a remoção de plasma seminal não proporcionou aumento da velocidade espermática, alteração no potencial de membrana mitocondrial e nem modificou o grau de peroxidação lipídica. Entretanto, a presença do plasma seminal (grupo controle) e a centrifugação provocou maiores índices de lesões na membrana plasmática, quando estas apresentam o acrossoma intacto (47,88±1,99% vs. 41,30±1,96%, respectivamente) em comparação ao grupo F (40,45±2,01%; p<0,07). A lesão em ambas as membranas (acrossomal e plasmática) foi mais evidente na filtragem (22,18±1,07) em relação ao grupo controle (15,23±1,06), sendo que a centrifugação não diferiu entre os grupos (17,43±1,04; p<0,01). A EROs foi mais evidente no grupo CE (56,68±4,53%) em relação ao grupo C e F (21,83±4,60% vs. 20,96±4,7%, respectivamente; p<0,01). Portanto, as hipóteses de que a remoção de plasma seminal melhoram a cinética espermática e proporcionam menores índices de lesões na membrana plasmática não foram confirmadas. Embora a filtragem tenha apresentado vantagem sobre a centrifugação gerando menor quantidade de EROs, não se justifica a remoção do plasma seminal em búfalos devido aos resultados serem muito semelhantes ao grupo controle.
Cryopreservation promotes injury to sperm and methods to minimize such damage are necessary. Although much discussed, removal of seminal plasma that has been successfully used in other species has become an alternative for improving sperm quality and viability after freezing. The aim of the present study was compare to removal seminal plasma in buffalo both by filtering (SpermFilter®) and by centrifugation on the quality frozen thawed buffalo semen. For this purpose, semen of seven Murrah buffalo-bulls, which were submitted to semen collection by artificial vagina once a week. The samples were diluted with Botu-Bov® and were fractionated in aliquots to confront three techniques before freezing: C group (conventional cryopreservation with seminal plasma), CE group (cryopreservation removing the seminal plasma centrifuge) F group (Cryopreservation removing the seminal plasma with Sperm Filter®). Fresh semen was analyzed for volume, appearance, color, concentration (Neubauer chamber), gross motility, progressive motility, vigor and sperm morphology. In the thawed sperm, sperm kinetics was evaluated by CASA, plasma membrane and acrosomal integrity, mitochondrial membrane potential and estimation of the levels of reactive oxygen species were assigned by flow cytometry and was estimated degree of lipid peroxidation by TBARS technique. The results show that the removal seminal plasma did not improve sperm kinetics, mitochondrial membrane potential and does not modify the degree of lipid peroxidation.However, the presence of seminal plasma (control group) and centrifugation resulted in higher rates of injury to the plasma membrane, where they have an intact acrosome (47,88±1,99% vs. 41,30±1,96%, respectively) compared to F group (40,45±2,01%; p<0.07). The damage in both membranes (acrosome and plasma) was more evident in filtering (22,18±1,07) compared to the control group (15,23±1,06), and centrifugation did not differ between groups (17,43±1,04; p<0.01). ROS production was more evident in the CE group (56,68±4,53%) compared to the C and F group (21.83±4.60% vs. 20.96±4.7%, respectively; p<0.01). Therefore, removal seminal plasmais not beneficial to sperm, as did not alter the sperm kinetics nor provided lower lesions rates in the plasma membrane, although the filter has presented advantage over centrifugation as generated lower amount of ROS, not justifies the use bothtechnique because the results are very similar to those with seminal plasma.
Cryopreservation promotes injury to sperm and methods to minimize such damage are necessary. Although much discussed, removal of seminal plasma that has been successfully used in other species has become an alternative for improving sperm quality and viability after freezing. The aim of the present study was compare to removal seminal plasma in buffalo both by filtering (SpermFilter®) and by centrifugation on the quality frozen thawed buffalo semen. For this purpose, semen of seven Murrah buffalo-bulls, which were submitted to semen collection by artificial vagina once a week. The samples were diluted with Botu-Bov® and were fractionated in aliquots to confront three techniques before freezing: C group (conventional cryopreservation with seminal plasma), CE group (cryopreservation removing the seminal plasma centrifuge) F group (Cryopreservation removing the seminal plasma with Sperm Filter®). Fresh semen was analyzed for volume, appearance, color, concentration (Neubauer chamber), gross motility, progressive motility, vigor and sperm morphology. In the thawed sperm, sperm kinetics was evaluated by CASA, plasma membrane and acrosomal integrity, mitochondrial membrane potential and estimation of the levels of reactive oxygen species were assigned by flow cytometry and was estimated degree of lipid peroxidation by TBARS technique. The results show that the removal seminal plasma did not improve sperm kinetics, mitochondrial membrane potential and does not modify the degree of lipid peroxidation.However, the presence of seminal plasma (control group) and centrifugation resulted in higher rates of injury to the plasma membrane, where they have an intact acrosome (47,88±1,99% vs. 41,30±1,96%, respectively) compared to F group (40,45±2,01%; p<0.07). The damage in both membranes (acrosome and plasma) was more evident in filtering (22,18±1,07) compared to the control group (15,23±1,06), and centrifugation did not differ between groups (17,43±1,04; p<0.01). ROS production was more evident in the CE group (56,68±4,53%) compared to the C and F group (21.83±4.60% vs. 20.96±4.7%, respectively; p<0.01). Therefore, removal seminal plasmais not beneficial to sperm, as did not alter the sperm kinetics nor provided lower lesions rates in the plasma membrane, although the filter has presented advantage over centrifugation as generated lower amount of ROS, not justifies the use bothtechnique because the results are very similar to those with seminal plasma.
Descrição
Palavras-chave
Bubalinos, Ejaculado, Centrifugação, Filtragem, Plasma seminal, Buffalo, Semen, Centrifugation, Filtering, Seminal plasma