title: Expression of orexins and their precursor in the porcine ovary and the influence of orexins on ovarian steroidogenesis in pigs.
abstract: Orexins A and B are hypothalamic neuropeptides associated with homeostasis and the reproductive system. The aim of the study was to compare the expression of the prepro-orexin gene and the intensity of orexins immunoreactivity in the porcine ovary (corpora lutea, granulosa and theca interna cells) during four different stages of the oestrous cycle (days: 2-3, 10-12, 14-16 and 17-19) and to examine the in vitro effect of orexins on the secretion of steroid hormones by porcine luteal, granulosa and theca interna cells. The highest expression of prepro-orexin mRNA was observed in theca interna cells on days 17-19 of the oestrous cycle. The highest content of immunoreactive orexin A was noted in corpora lutea on days 10-12 and the highest level of immunoreactive orexin B on days 14-16 of the cycle. Immunoreactive orexin A concentrations were higher in theca interna cells than in granulosa cells, whereas similar levels of immunoreactive orexin B were observed in both cell types. Under in vitro conditions, at the concentration of 10 nM, orexins A and B inhibited FSH-induced oestradiol secretion by granulosa cells. The obtained results suggest that the pattern of orexin peptide expression in the porcine ovary is related to the animals' hormonal status. Our findings imply that orexins can affect porcine reproductive functions through modulation of ovarian steroidogenesis.
authors.affiliation: Department of Animal Physiology, University of Warmia and Mazury in Olsztyn, ul. Oczapowskiego 1A, 10-719 Olsztyn, Poland.
authors.forename: Anna
authors.initials: A
authors.lastname: Nitkiewicz
authors.affiliation: Department of Animal Physiology, University of Warmia and Mazury in Olsztyn, ul. Oczapowskiego 1A, 10-719 Olsztyn, Poland.
authors.forename: Nina
authors.initials: N
authors.lastname: Smolinska
authors.affiliation: Department of Animal Physiology, University of Warmia and Mazury in Olsztyn, ul. Oczapowskiego 1A, 10-719 Olsztyn, Poland.
authors.forename: Anna
authors.initials: A
authors.lastname: Maleszka
authors.affiliation: Department of Animal Physiology, University of Warmia and Mazury in Olsztyn, ul. Oczapowskiego 1A, 10-719 Olsztyn, Poland.
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Chojnowska
authors.affiliation: Department of Animal Physiology, University of Warmia and Mazury in Olsztyn, ul. Oczapowskiego 1A, 10-719 Olsztyn, Poland. Electronic address: tkam@uwm.edu.pl.
authors.forename: Tadeusz
authors.initials: T
authors.lastname: Kaminski
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D005260:Female; D005786:Gene Expression Regulation / Q000502:physiology*; D047908:Intracellular Signaling Peptides and Proteins / Q000235:genetics / Q000378:metabolism*; D009479:Neuropeptides / Q000235:genetics / Q000378:metabolism*; D000068797:Orexins; D010053:Ovary / Q000166:cytology / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D013256:Steroids / Q000096:biosynthesis*; D013552:Swine / Q000502:physiology*
chemical_list: D047908:Intracellular Signaling Peptides and Proteins; D009479:Neuropeptides; D000068797:Orexins; D012333:RNA, Messenger; D013256:Steroids
keywords: Corpus luteum; Granulosa cells; Orexin; Pig; Steroid hormones; Theca interna cells