Influence of glycerol addition on the quality of cat epididymal sperm during the freeze-thaw process

• Autor(a) principal: Barbosa, Brenna de Sousa
• Data de Publicação: 2020
• Outros Autores: Silva, Herlon Victor Rodrigues, Silva, Ticiana Franco Pereira da, Silva, Lúcia Daniel Machado da
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Semina. Ciências Agrárias (Online)
• Texto Completo: https://ojs.uel.br/revistas/uel/index.php/semagrarias/article/view/36574
• topic: Cryo-injury; Cryopreservation; Sperm; Feline; Intracellular cryoprotectant.; Criodanos. Criopreservação; Espermatozoide; Felino; Crioprotetor intracelular.

Cryopreservation of epididymal sperm is a useful tool for preserving the genetic potential of valuable animal specimens. The domestic cat is used as a model to study and develop cryogenics for other felines. However, regulation of the entire cryopreservation process is essential for the success of this biotechnology. Thus, our aim was to evaluate the effects of glycerol equilibration time and freeze-thaw stages on the quality of epididymal sperm obtained from domestic cats. Epididymal sperm were recovered with TRIS and immediately evaluated for total motility (TM), vigor, viability, membrane functionality (HOST), and morphology. Then, TRIS-20% egg yolk was added to the samples, which were equally divided into two 1.5 mL tubes and refrigerated at 4 ºC for 1 hour. Subsequently, glycerol was added at a final concentration of 5%. The samples were incubated with glycerol (equilibration time) for either 5 or 10 minutes (groups G5 and G10, respectively) and then frozen. Thawing occurred at 37 ºC for 30 seconds. The samples were evaluated at all stages. A reduction in TM was observed only after thawing; however, it was higher in G5 (39.00 ± 4.07%) than in G10 (18.50 ± 4.54%). Vigor declined in both groups after thawing; however, they did not differ from each other. Sperm viability was maintained in G5 after glycerolization (53.60 ± 2.59%); in G10, sperm viability decreased in the glycerolized sample (48.80 ± 2.93%) when compared to that in the fresh sample (59.90 ± 1.74%). Post-thaw viability of G5 (33.80 ± 1.89%) was higher than that of G10 (18.80 ± 3.01%). In the HOST, a decrease in viability was only observed after thawing, with no difference between the groups (41.50 ± 2.84% for G5 and 40.20 ± 3.49% for G10). With regard to sperm morphology, normal sperm decreased while sperm with post-thaw secondary defects increased in both groups. In conclusion, a shorter equilibration time for glycerolization preserves epididymal sperm quality better and the freeze-thaw process is the most critical stage of thawing.