Person:
Gutiérrez Cepeda, Luna

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First Name
Luna
Last Name
Gutiérrez Cepeda
URI
https://hdl.handle.net/20.500.14352/80365
Affiliation
Universidad Complutense de Madrid
Faculty / Institute
Veterinaria
Department
Medicina y Cirugía Animal
Area
Medicina y Cirugía Animal
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2011 - 20133
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Author: Gosálvez Berenguer, Jaime ×

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Now showing 1 - 3 of 3
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    Simple and economic colloidal centrifugation protocols may be incorporated into the clinical equine sperm processing procedure
    (Animal Reproduction Science, 2011) Gutiérrez Cepeda, Luna; Fernández, A; Crespo Castejón, Francisco; Gosálvez Berenguer, Jaime; Serres Dalmau, María Consolacion
    For many years in human assisted-reproduction procedures there have been special protocols to prepare and improve sperm quality. Colloidal centrifugation (CC) is a useful technique that has been proved to enhance semen quality by selection of the best spermatozoa for different species. Its use is recommended to improve fertility of subfertile stallions but current CC protocols are clinically complicated in the equine sperm processing technique due to economic and technical difficulties. The aim of this study was to determine the optimal processing procedures to adapt the use of a CC product (EquiPure™) in the equine reproduction industry. A total of nineteen ejaculates were collected from 10 Purebred Spanish Horses (P.R.E horses) using a Missouri artificial vagina. Gel-free semen aliquots were analyzed prior to treatment (control). Semen was subjected to one of six CC protocols with EquiPure™ and centrifuged samples were statistically evaluated by ANOVA and Duncan tests (p<0.05) for sperm quality and recovery rate. We obtained higher values by colloidal centrifugation in LIN, STR and BCF variables and DNA fragmentation index trended to be lower in most of the CC protocols. The studied protocols were shown to be as efficient in improving equine sperm quality as the current commercial EquiPure™, with the added advantage of being much more economical and simple to use. According to these results it seems to be possible to incorporate single layer and or high colloidal centrifugation volume protocols what would make them simple, economic and clinically viable for the equine sperm processing procedure.
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    Colloidal centrifugation of stallion semen results in a reduced rate of sperm DNA fragmentation
    (Reproduction Domestic Animals, 2013) Gosálvez Berenguer, Jaime; Crespo Castejón, Francisco; Gutiérrez Cepeda, Luna; Serres Dalmau, María Consolacion; Jonhnston, Stephen
    Stallion spermatozoa recovered and examined immediatelyafter colloidal centrifugation resulted in a higher straight-linevelocity (VSL) than sperm processed using direct conven-tional centrifugation (p = 0.000), but there was nodifferences in the progressive motility or sperm DNAfragmentation (SDF) as determined by the sperm chromatindispersion assay. However, when centrifuged spermatozoawere incubated at 37°C for 24 h to determine the rate of SDF(r-SDF), a lower r-SDF (p = 0.0011) was observed in thosesperm recovered after colloidal separation (0.5 ± 0.1%⁄h)compared to direct (1.2 ± 0.4%⁄h) or no centrifugation (r-SDF = 1.2 ± 0.3%⁄h). These results confirm that colloidalseparation of stallion spermatozoa results in prolonged spermDNA longevity, but these differences were only apparentfollowing a period of incubation and dynamic assessment.Consequently, we strongly recommend the use of thedynamic form of the SDF assay for evaluating centrifugationand⁄or otherex vivoprocedures, as a single basal assessmentof SDF may inadvertently result in a false-positive evaluationof DNA quality.
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    The effect of two pre-cryopreservation single layer colloidal centrifugation protocols in combination with different freezing extenders on the fragmentation dynamics of thawed equine sperm DNA
    (Acta Veterinaria Scandinávica, 2012) Gutiérrez Cepeda, Luna; Fernández, Alvaro; Crespo Castejón, Francisco; Ramírez, Miguel Ángel; Gosálvez Berenguer, Jaime; Serres Dalmau, María Consolacion
    Variability among stallions in terms of semen cryopreservation quality renders it difficult to arrive at a standardized cryopreservation method. Different extenders and processing techniques (such us colloidal centrifugation) are used in order to optimize post-thaw sperm quality. Sperm chromatin integrity analysis is an effective tool for assessing such quality. The aim of the present study was to compare the effect of two single layer colloidal centrifugation protocols (prior to cryopreservation) in combination with three commercial freezing extenders on the post-thaw chromatin integrity of equine sperm samples at different post-thaw incubation (37°C) times (i.e., their DNA fragmentation dynamics). Results Post-thaw DNA fragmentation levels in semen samples subjected to either of the colloidal centrifugation protocols were significantly lower (p<0.05) immediately after thawing and after 4 h of incubation at 37°C compared to samples that underwent standard (control) centrifugation. The use of InraFreeze® extender was associated with significantly less DNA fragmentation than the use of Botu-Crio® extender at 6 h of incubation, and than the use of either Botu-Crio® or Gent® extender at 24 h of incubation (p<0.05). Conclusions These results suggest that single layer colloidal centrifugation performed with extended or raw semen prior to cryopreservation reduces DNA fragmentation during the first four hours after thawing. Further studies are needed to determine the influence of freezing extenders on equine sperm DNA fragmentation dynamics.