Medicina Veterinaria
URI permanente para esta comunidadhttps://dspace.ucacue.edu.ec/handle/ucacue/52
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Examinando Medicina Veterinaria por Asesores "Moscoso Piedra, Andrés Leonardo"
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Ítem Acceso Abierto Determinación del efecto post congelación de microdosis de menaquinona-4 en semen ovino(Universidad Católica de Cuenca., 2025) Farfán Alvarado, Karen Dayana; Moscoso Piedra, Andrés Leonardo; 0705823151The ovine semen presents particularly high levels of polyunsaturated fatty acids (PUFAs) in its plasma membrane. This composition causes high instability, making sperm cells prone to reactive oxygen species (ROS) formation. Oxidative stress (OS), triggered by thermal shock and atmospheric oxygen during cryopreservation, increases susceptibility to lipid peroxidation (LPO). Antioxidant supplementation acts and reacts as a protective strategy against this damage. This study proposed Menaquinone-4 (MK-4), a vitamin K homolog from the Menaquinone group, as a potential sperm antioxidant. We tested in the Reproduction Laboratory at Universidad Católica de Cuenca three microdoses of MK-4 (0.5 µM, 1 µM, 2 µM) to assess its effect on post-thaw ovine semen. Results showed dose-dependent variability compared to the control. At 2 µM, membrane integrity parameters were similar to the control. However, the 0.5 µM dose improved progressive motility. These differences suggest that MK-4 efficacy depends on the enzymatic capacity of sperm cells. The absence of UBIAD1 enzyme in donor gonads, due to the lack of endoplasmic reticulum and Golgi apparatus in sperm cells, limits MK-4 utilization. Therefore, antioxidant performance depends on intracellular enzyme availability. This biochemical limitation explains the inconsistent results across doses. MK-4 may offer cryoprotective benefits under specific cellular conditions, particularly in sperm with active metabolic machinery. Findings highlight the importance of considering enzymatic context when using fat-soluble antioxidants in cryopreservation protocols. Further research is needed to optimize MK-4 concentrations and evaluate its in vivo impact on fertility parameters. Keywords: PUFA; EO; LPO; ROS; UBIAD1Ítem Embargo Efecto de hembras estrogenizadas sobre el comportamiento sexual y la calidad seminal del carnero.(Universidad Católica de Cuenca., 2025) Labanda Sigcho, Jorge Eduardo; Moscoso Piedra, Andrés Leonardo; 0107329237.Ítem Acceso Abierto Efecto de la concentración de la L-carnitina en congelación del semen ovino(Universidad Católica de Cuenca., 2025) Valdez Pinoargote, Girabel Gissela; Moscoso Piedra, Andrés Leonardo; 0804298040Sperm cryopreservation is a key technique in animal reproduction, particularly in ruminants, enabling assisted reproduction and benefiting veterinary medicine. L-Carnitine, an amino acid derived from lysine and methionine, plays a crucial role in preserving membrane integrity and mitochondrial function. The aim of this study was to assess the effect of Lcarnitine supplementation at doses of 1M, 0.750mM, 0.500mM, and 0.100mM on the sperm quality of three sheep breeds (Dorper, Kathadin, and Pelibuey). Semen was collected from each sheep over multiple mounts, resulting in three ejaculates per animal, with a total of nine samples, and a control test with semen free of L-carnitine. These samples were evaluated through laboratory tests (Eosin-Nigrosin, Propidium Iodide, and Rodamine) and analyzed using the CASA system to measure parameters such as PR, NP, IM, VCL, VAP, VSL, STR, LIN, ALH, and BCF. The results favored the 1M dose (highest concentration) across permeability, viability, and kinetics tests. Statistical differences were found in the LIN and STR values, consistently favoring the 1M concentration compared to the control. Keywords: Cryopreservation; L-Carnitine; Sheep; SpermatozoaÍtem Embargo Microdosis de coenzima Q10 como potencializador de la calidad espermática de semen ovino crioconservado(Universidad Católica de Cuenca., 2025) Quinche Guazhambo , Mónica Daniela; Moscoso Piedra, Andrés Leonardo; 0106979446.Ítem Acceso Abierto Proyecto de titulación embargado con fines de publicación de impacto(Universidad Católica de Cuenca., 2025) Guiracocha Viñanzaca, Ingrid Michelle; Moscoso Piedra, Andrés Leonardo; 0107568669
