Expression of melanocortin receptors mRNA, and direct effects of ACTH on steroids secretion in the bovine ovary.

AMWEG, AN; PAREDES, A.; SALVETTI, NR; LARA, HE; ORTEGA, HH

THERIOGENOLOGY

ELSEVIER SCIENCE INC

Año: 2011 p. 628 - 637

0093-691X

Melanocortin receptors (MCRs) are involved in the physiological responses to ACTH and alpha, beta- and gamma-melanocyte-stimulating hormone (alpha-, beta- and gamma-MSH). Their expression has been previously analysed in different bovine tissues; however, there are no previous studies about their localisation in the ovaries. We examined the expression of MCR mRNA in bovine ovaries using reverse transcription polymerase chain reaction (RT-PCR). MC1R, MC2R MC3R, MC4R and MC5R mRNA were localised in the theca of different follicular stages, whereas only MC3R mRNA was weakly evidenced in granulosa cells. MC1R, MC2R and MC3R mRNA were found in the corpora lutea. In stroma only MC2R mRNA was expressed. These results confirm earlier reports in other species, and demonstrate that MCRs are present in bovine ovaries. The fact that ACTH was able to induce steroid secretion from the ovary in vitro strongly suggest that melanocortin peptides could be involved in regulatory mechanisms related to ovarian function associated to ovulation, steroidogenesis and luteal function.