Examinando por Materia "Gonadotropins"

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Induction of superovulation in South American camelids
(Elsevier B.V., 2013-01-10) Ratto, Marcelo H.; Silva, Mauricio E.; Huanca López, Wilfredo; Huanca Mamani, Teodosio; Adams, Gregg Patrick
The development of assisted reproductive technologies such as embryo transfer (ET), artificial insemination (AI) and in vitro fertilization (IVF) in South American camelids is considerably behind that of other livestock species. Poor success of the embryo transfer technique has been related to a lack of an effective superstimulatory treatment, low embryo recovery rate, and the recovery of hatched blastocysts that are not conducive to the cryopreservation process. Superstimulation has been attempted using equine chorionic gonadotropin (eCG) and follicle stimulating hormone (FSH) during the luteal, or the sexually receptive phase, sometimes given at follicular wave emergence. The rationale for inducing a luteal phase prior to or during superstimulation in camelids is not clearly understood, but it may simply reflect an empirical bias to conventional methods used in other ruminants. The number of ovulations or CL varies widely among studies, ranging from 2 to more than 15 per animal, with the number of transferable embryos ranging from 0 to 4 per animal. The control of follicular growth combined with superstimulatory protocols has resulted in a more consistent ovarian response and a greater number of follicles available for aspiration and oocyte collection. Recent studies in llamas have demonstrated that the use of ovulation inducing treatments or follicle ablation can synchronize follicular wave emergence allowing the initiation of gonadotropin treatment in the absence of a dominant follicle resulting in a more consistent ovulatory response. Few studies in alpacas have been reported, but it appears from recent field studies that the ovarian response is more variable and that there is a greater number of poor responders than in llamas. A review of superstimulation protocols that have been used in llamas and alpacas in the last 15 years is provided, including a discussion of the potential of protocols designed to initiate treatment at specific stages of follicular growth.
Influencia de las hormonas folículo estimulante, luteinizante y gonadotropina coriónica equina en la maduración in vitro de ovocitos y clivaje de embriones de alpaca
(Universidad Nacional del Altiplano. Escuela de Postgrado, 2019-03-29) Quispe Gutiérrez, Ulises S.; Huanca Mamani, Tedosio; Olivera Marocho, Luis V.
ford La producción de embriones in vitro de alpacas está aún en etapas iniciales. El objetivo fue evaluar la influencia de hormonas folículo estimulante (FSH), luteinizante (LH) y gonadotropina coriónica equina (eCG) en la maduración in vitro de ovocitos y clivaje de embriones de alpacas. Realizado en el Laboratorio de Fertilización in vitro del CIP Quimsachata, Estación Experimental ILLPA Puno. Los ovocitos se recuperaron de ovarios de alpaca faenadas, los de categoría A y B fueron madurados en medio TCM –199 (Incubadora a 6.1% de CO2; 5% de O2; 38.5 °C con alta humedad), en grupos de tratamientos (T) suplementados con gonadotropinas, T1: eCG 15 UI mL-1sinFSH y LH; T2: FSH 0.25 μg mL -1 + LH 2.5 μg mL -1 sin eCG; T3: FSH 0.25 μg mL -1 + LH 2.5 μg mL -1 + eCG15UI mL-1, durante 36 h, luego, fertilizados con 2 μL de semen (4 x 106 espermatozoides mL-1) en medio Fertil TALP por 12 h y cultivados en medio SOF por 48 h. Se obtuvo mayor porcentaje (P≤ 0.05) de ovocitos en metafase II: 46.9% en T3, 41.0% en T2 versus T1. Se encontró mayor tasa (P≤ 0.05) de clivaje (2 a 8 células a 48 h de cultivo): 22.4% en T3, 17.8% en T2en comparación con T1. Se concluye que las gonadotropinas FSH, LH afectan positivamente la maduración de ovocitos in vitro repercutiendo en el clivaje de embriones de alpacas.