INICSA   23916
INSTITUTO DE INVESTIGACIONES EN CIENCIAS DE LA SALUD
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Use of urinary biomarkers of ovarian function in Chinchilla lanigera: assessing protocols for synchronization and ovulation induction.
Autor/es:
DEMARIA C; MASTROMONACO G; PONZIO MF; CANTARELLI VI; PINO M
Reunión:
Conferencia; 7th Conference of the International Society of Wildlife Endocrinology; 2019
Resumen:
Due to the high value of its fur, indiscriminate hunting reduced chinchilla wild populations virtually to the verge of extinction (IUCN critically endangered, CITES Appendix I). A key aspect for the implementation of ex-situ captive breeding programs is the study of the species? reproductive physiology. Our objective was to evaluate the endocrine patterns of ovarian dynamics after its exogenous activation in chinchillas, using luteolytic pre-treatments with prostaglandin-F2α (PG-F2α). Two doses of PG-F2α were tested: Cloprostenol sodium 50 and 100 µg (Ciclase-DL); ovulation was then induced using eCG 100 U.I. (Novormon-5000) and hCG 80 U.I (Ovusyn). Eight females were randomly assigned to each protocol and urine samples collected before, during and a week after the drugs i.m. injection. Samples were analyzed for creatinine (CRT, Sigma #C3613), pregnanediol glucuronide and estrone conjugates (PdG-R13904, EC-R522-2, C.Munro) by EIA. A longitudinal profile was obtained for each hormone and female, using an iterative process to calculate baseline and peak hormonal levels. Although both prostaglandin doses kept progestagen concentrations at basal levels until the application of the inductor (eCG), a more synchronic response afterwards was obtained with the higher PG-F2α dosis. Using this protocol, 87.5% of the females showed a positive response to eCG at day 8 post-PG followed by hCG at day 13, observing an increase in EC concentration twelve times above baseline levels (0.34±0.06 vs. 4.3±1.03 ng/mg CRT) followed by a PdG peak of fourteen times above baseline levels (153.4±39.9 vs. 2133.7±892.4 ng/mg CRT). EC peak duration was 5,1±0,6 days in coincidence with the natural cycle in chinchillas ( 6.7±0.9 days). However, PdG peak duration was 3.5±0.5 days, which suggests the occurrence of a very short luteal phase in relation to what occurs in the natural cycle (7.1±0.6 days). Further studies are needed in order to accurately imitate the natural cycle.