Luteotrophic effect of GnRH or hCG on corpus luteum functionality during the luteal phase in ewes.

FERNANDEZ J; BRUNO GALARRAGA, MARÍA MACARENA;; SOTO, A; DE LA SOTA, R.L.; CUETO MARCELA; ULISES NOTARO; NATALIA SALVETTI; HUGO ORTEGA; ALEJANDRO GIBBONS; ISABEL LACAU- MENGIDO

Jornada; Reunión anual de Sociedades Biocientíficas (LXIV SAIC, LI SAFE, XXI SAB, XXXI SAP).; 2020

LXIV SAIC, LI SAFE, XXI SAB, XXXI SAP

Different therapeutic strategies have been used with the objective of increasing theconcentration of progesterone (P4) and improving luteal function in order to reduce embryoniclosses. The objective of the study was to determine the effect of gonadotrophin releasinghormone (GnRH) or human chorionic gonadotrophin (hCG) treatment at 4 days after timedartificial insemination (TAI) on the induction of accessory corpora lutea (acc-CL), the productionand synthesis of P4. A total of 27 adult Merino ewes were randomly assigned to three groups onday 4 post TAI: GnRH group (n= 9; 4 μg IM of GnRH analogue, Receptal®, Intervet, Argentine),hCG group (n= 9; 300 IU IM of hCG, Gonacor®, Ferring, Argentine) and Control group (n= 9; 1 mlIM of saline solution). Laparoscopic observations of the ovaries on days 4 and 10 post TAI wereperformed to determine the presence of ovulatory CL (o-CL) and acc-CL, respectively. Serum P4concentration was assessed by chemiluminescence on days 4, 7 and 14 post TAI. On day 14 postTAI, o-CL and acc-CL were removed (n=3 ewes per each treatment) to determine STAR and 3β-hydroxysteroid dehydrogenase (3β-HSD) expressions by immunohistochemistry. The resultswere analyzed by ANOVA. The GnRH and hCG treated groups had a higher number of acc-CLcompared to the control group (1.3±0.1 vs. 0.0±0.0, P