Associação entre a Na+, K+-ATPase e a fertilidade de amostras seminais descongeladas de touros Angus

• Autor(a) principal: Marques, Juliana Carla Cavalcanti
• Data de Publicação: 2019
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da Universidade Federal de Alagoas (UFAL)
• Texto Completo: http://www.repositorio.ufal.br/handle/riufal/7001
• topic: Bomba de sódio; Sodium-potassium pump; Bovino; Bovine; Espermatozoide; Sperm; CNPQ::CIENCIAS AGRARIAS::MEDICINA VETERINARIA

Currently, one of the challenges on bovine reproduction is to efficiently identify high fertility bulls, since traditional andrological evaluation may not precisely differ the fertilizing potential of a sire, leading to reduced pregnancy rates and economic losses. Therefore, the Na+, K+-ATPase has been considered a potential fertility marker, due to its sperm specific properties and reports o correlation with Holstein bull fertility. However, specificities on reproductive management of Brazilian beef herds associated to the lack of information regarding Na+, K+-ATPase in beef bulls, the present study was performed aiming to determine association between Na+, K+- ATPase activity in thawed Angus bull sperm scored as being a high fertility (HF) or normal fertility (NF) after fixed time artificial insemination (FTAI). Samples from three different commercial batches of bulls of HF (n=4) or NF (n=4) were used. Sperm kinematics was evaluated with CASA system, sperm viability was assessed by fluorescent microscopy, and expression of Na+, K+-ATPase on the sperm surface by flow citometry, immediately post-thaw (0h) and after 2h of incubation (37 °C). Na+, K+-ATPase activity was determined measuring the releasing of inorganic phosphate (iP) in the samples treated or not with a specific inhibitor (ouabain, 4×10-4 M), normalized by total protein of each sample. Within the same incubation time, there was no difference (P > 0.05) on sperm viability, kinematic parameters, and the expression of Na+, K+-ATPase between HF and NF bulls. Kinematic parameters of LIN and VCL were not influenced (P>0.05) by incubation time in samples from HF and NF, respectively. There was a tendency (P=0.06) of higher Na+, K+-ATPase enzymatic activity in HF bull samples. In conclusion, differences on kinematic and sperm viability are not detected between HF and NF Angus bulls immediately postthaw. Different responses on velocity parameters post-incubation were detected in HF and NF bulls that might be related to Na+, K+-ATPase activity, without influence of Na+, K+-ATPase expression.