title: Tissue-specific regulation of porcine prolactin receptor expression by estrogen, progesterone, and prolactin.
abstract: Prolactin (PRL) acts through its receptor (PRLR) via both endocrine and local paracrine/autocrine pathways to regulate biological processes including reproduction and lactation. We analyzed the tissue- and stage of gestation-specific regulation of PRL and PRLR expression in various tissues of pigs. Abundance of pPRLR-long form (LF) mRNA increased in the mammary gland and endometrium during gestation while in other tissues it remained constant. There was a parallel increase in the abundance of the pPRLR-LF protein in the mammary gland and endometrium during gestation. We determined the hormonal regulation of pPRLR-LF mRNA expression in various tissues from ovariectomized, hypoprolactinemic gilts given combinations of the replacement hormones estrogen (E(2)), progestin (P), and/or haloperidol-induced PRL. Abundance of pPRLR-LF mRNA in kidney and liver was unaffected by hormone treatments. Expression of uterine pPRLR-LF mRNA was induced by E(2) whereas the effect of E(2) was abolished by co-administering P. The expression of pPRLR-LF mRNA in the mammary gland stroma was induced by PRL, whereas E(2) induced its expression in the epithelium. In contrast to these changes in pPRLR expression, pPRL expression was relatively constant and low during gestation in all tissues except the pituitary. Taken together, these data reveal that specific combinations of E(2), P, and PRL differentially regulate pPRLR-LF expression in the endometrium and mammary glands, and that the action of PRL on its target tissues is dependent upon pPRLR-LF abundance more so than the local PRL expression.
authors.affiliation: Lactation and Mammary Gland Biology Group, Department of Animal Science, The University of Vermont, Burlington, Vermont 05405, USA.
authors.forename: Josephine F
authors.initials: JF
authors.lastname: Trott
authors.forename: Katherine C
authors.initials: KC
authors.lastname: Horigan
authors.forename: Julia M
authors.initials: JM
authors.lastname: Gloviczki
authors.forename: Kristen M
authors.initials: KM
authors.lastname: Costa
authors.forename: Bradley A
authors.initials: BA
authors.lastname: Freking
authors.forename: Chantal
authors.initials: C
authors.lastname: Farmer
authors.forename: Kanako
authors.initials: K
authors.lastname: Hayashi
authors.forename: Thomas
authors.initials: T
authors.lastname: Spencer
authors.forename: Joseph E
authors.initials: JE
authors.lastname: Morabito
authors.forename: Russell C
authors.initials: RC
authors.lastname: Hovey
mesh_terms: D000818:Animals; D004338:Drug Combinations; D004717:Endometrium / Q000187:drug effects / Q000378:metabolism; D004967:Estrogens / Q000494:pharmacology*; D005260:Female; D005786:Gene Expression Regulation / Q000187:drug effects; D005865:Gestational Age; D007774:Lactation / Q000235:genetics / Q000378:metabolism; D008321:Mammary Glands, Animal / Q000187:drug effects / Q000378:metabolism; D009928:Organ Specificity / Q000187:drug effects / Q000235:genetics; D011247:Pregnancy; D011270:Pregnancy, Animal; D011374:Progesterone / Q000494:pharmacology*; D011388:Prolactin / Q000494:pharmacology*; D011981:Receptors, Prolactin / Q000235:genetics* / Q000378:metabolism; D013552:Swine / Q000235:genetics* / Q000378:metabolism; D014018:Tissue Distribution
chemical_list: D004338:Drug Combinations; D004967:Estrogens; D011981:Receptors, Prolactin; D011374:Progesterone; D011388:Prolactin