MC2R/MRAP2 activation could affect bovine ovarian steroidogenesis potential after ACTH treatment

ETCHEVERS, L.; BELOTTI, E.M.; DÍAZ, P.U.; RODRÍGUEZ, F.M.; REY, F.; SALVETTI, N.R.; ORTEGA, H.H.; AMWEG, A.N.

THERIOGENOLOGY

ELSEVIER SCIENCE INC

Año: 2021

0093-691X

Stressors activate the hypothalamic?pituitary?adrenal (HPA) axis, reducing fertility by interfering with the mechanisms that regulate the timing of events within the follicular phase of the estrous cycle. In the HPA axis, melanocortin 2 receptor (MC2R) mediates responses to adrenocorticotropic hormone (ACTH) in concert with melanocortin receptor accessory protein 2 (MRAP2). The aims of the present study were: (1) to evaluate the effects of ACTH administered in cows in the preovulatory period on the expression of the MC2R/MRAP2 complex in the dominant follicle; and (2) to analyze the involvement of Extracellular signal Regulated Kinase 1 (ERK1) signaling in the activation of MC2R and the expression of key enzymes involved in the biosynthesis of glucocorticoids (GCs) in the dominant follicle. To this end, 100 IU ACTH was administered to Holstein cows from a local dairy farm during pro-estrus every 12 hours for four days until ovariectomy, which was performed before ovulation. Protein immunostaining of MC2R was higher in the dominant follicles of ACTH-treated cows (p