Luteotrophic effect of gnrh or hcg on corpus luteum functionality during the luteal phase in ewes

FERNANDEZ, J; BRUNO GALARRAGA, M; SOTO, A; DE LA SOTA, L; CUETO, M; NOTARO, U; SALVETTI, N; ORTEGA, H; GIBBONS, A; LACAU-MENGIDO, I

Congreso; XXI Reunión Anual de la Sociedad Argentina de Biología (SAB); 2019

Different therapeutic strategies have beenused with the objective of increasing the concentration ofprogesterone (P4) and improving luteal function in order toreduce embryonic losses. The objective of the study was todetermine the effect of gonadotrophin releasing hormone (GnRH)or human chorionic gonadotrophin (hCG) treatment at 4 daysafter timed artificial insemination (TAI) on the induction ofaccessory corpora lutea (acc-CL), the production and synthesis ofP4. A total of 27 adult Merino ewes were randomly assigned tothree groups on day 4 post TAI: GnRH group (n= 9; 4 µg IM ofGnRH analogue, Receptal®, Intervet, Argentine), hCG group (n=9; 300 IU IM of hCG, Gonacor®, Ferring, Argentine) and Controlgroup (n= 9; 1 ml IM of saline solution). Laparoscopicobservations of the ovaries on days 4 and 10 post TAI wereperformed to determine the presence of ovulatory CL (o-CL) andacc-CL, respectively. Serum P4 concentration was assessed bychemiluminescence on days 4, 7 and 14 post TAI. On day 14post TAI, o-CL and acc-CL were removed (n= 5 ewes per eachtreatment) to determine STAR and 3ß-hydroxysteroiddehydrogenase (3ß-HSD) expressions by immunohistochemistry.The results were analyzed by ANOVA. The GnRH and hCG treatedgroups had a higher number of acc-CL compared to the controlgroup (1.3 ± 0.1 vs. 0.0 ± 0.0, p