Science and Technology Production
Revista Medicina - Luteotrophic effect of gnrh or hcg on corpus luteum functionality during the luteal phase in ewes
Congreso
Authorship:
Fernandez, J ; Bruno Galarraga, M ; Soto, A ; De la Sota, L ; Cueto, M ; NOTARO, ULISES SEBASTIÁN ; Salvetti, N ; Ortega, H ; Gibbons, A ; Lacau-Mengido, IDate:
2019Publishing House and Editing Place:
Ethel Di VitaSummary *
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<0.01). The administration ofhCG increased serum P4 concentrations on days 7 and 14 postTAI (4.2 ± 0.4, 12.1 ± 1.4 ng/ml) compared to GnRH group (3.1± 0.4, 8.5 ± 1.4 ng/ml) and the Control group (3.5 ± 0.4, 6.7 ±1.4 ng/ml; p<0.05). The STAR and 3ß-HSD positive cell/areatissue of both o-CL and acc-CL were higher in the hCG groupthan GnRH and Control groups (p<0.05). In conclusion,administration of hCG or GnRH on day 4 post TAI induced theformation of an acc-CL. However, serum concentration of P4 andsome members of the progesterone synthesis pathway increasedsignificantly only in the hCG group, evidencing differentsteroidogenic capacity of this hormone. Information provided by the agent in SIGEVAKey Words
EWECORPUS LUTEUMHCGGNRH