The aim of the present study was to evaluate the susceptibility of the corpus luteum to cloprostenol sodium (synthetic analog of PGF2α) during development of the luteal phase in alpacas after induced ovulation with seminal plasma or GnRH. Semen was collected from male alpacas using an artificial vagina and then diluted 1/1 with phosphate buffered saline (PBS), centrifuged and stored at -20 °C. Females alpacas (n=96) bearing ≥7 mm follicles in their ovaries were induced to ovulate by injecting seminal plasma (n=48) and GnRH (n=48). Animal that ovulate were randomly assigned into one of six groups: control and treated with an injection of cloprostenol sodium on days 4, 5, 6, 7 and 8 post-ovulation. Blood samples were collected to determine serum progesterone concentrations at baseline and 24 hours post-injection of cloprostenol sodium. The was no luteolytic effect of PGF2α in animals treated on day 4 or 5, whereas animals treated on day 6, 7 or 8 were responding with effective luteolysis at 24 hours post-PGF2α showing a reduction in size of the corpus luteum and progesterone levels close or lower than <1 ng/ml. In conclusion, corpora lutea obtained by induced ovulation using seminal plasma or GnRH are susceptible to luteolysis from day 6 onwards after stimulation of ovulation.
Camilo Mamani, M., Wilfredo Huanca, L., Luisa Echevarría, C., Cordero, A., Willian Fahrid Huanca, M., & Tito Limache, C. (2016). Susceptibility of the corpus luteum to prostaglandin F<inf>2α</inf> in alpacas after induced ovulation with seminal plasma and GNRH. Revista de Investigaciones Veterinarias del Peru, 729-735. https://doi.org/10.15381/rivep.v27i4.12558