title: Direct effects of prolactin on adrenal steroid release in male Hatano high-avoidance (HAA) rats may be mediated through Janus kinase 2 (Jak2) activity.
abstract: Prolactin (PRL) has been proposed to directly stimulate corticosterone release. However, the role of PRL on adrenocortical function in male HAA rats has not been fully clarified. The aim of this study was to investigate the effect of PRL on the secretion of corticosterone and progesterone using an in vitro cell culture system in male rats. Administration of PRL (10(-7) and 10(-6) M) resulted in dose-dependent increases in corticosterone and progesterone release. Cotreatment with PRL produced an increase in the stimulatory effects of ACTH-induced corticosterone and progesterone secretion. However, the PRL-induced corticosterone and progesterone releases were significantly reduced by treatment with AG490, a specific Janus kinase 2 (Jak2) inhibitor. In addition, administration of AG490 blunted the significant inhibition of ACTH-induced corticosterone and progesterone secretion by PRL. These results demonstrated that PRL could act directly on the adrenal gland to drive corticosterone and progesterone secretion in male rats. Additionally, the results emphasize that PRL stimulation of adrenal steroid release may be mediated through Jak2 activity.
authors.affiliation: Department of Basic Veterinary Science, The United School of Veterinary Sciences, Gifu University, Gifu, Japan.
authors.forename: Sukanya
authors.initials: S
authors.lastname: Jaroenporn
authors.forename: Kentaro
authors.initials: K
authors.lastname: Nagaoka
authors.forename: Ryo
authors.initials: R
authors.lastname: Ohta
authors.forename: Gen
authors.initials: G
authors.lastname: Watanabe
authors.forename: Kazuyoshi
authors.initials: K
authors.lastname: Taya
mesh_terms: D000302:Adrenal Cortex / Q000166:cytology / Q000201:enzymology* / Q000378:metabolism; D000324:Adrenocorticotropic Hormone / Q000378:metabolism; D000818:Animals; D001362:Avoidance Learning; D002478:Cells, Cultured; D003345:Corticosterone / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000494:pharmacology; D066298:In Vitro Techniques; D053614:Janus Kinase 2 / Q000037:antagonists & inhibitors / Q000378:metabolism*; D008297:Male; D011374:Progesterone / Q000378:metabolism; D011388:Prolactin / Q000378:metabolism* / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology; D020032:Tyrphostins / Q000494:pharmacology
chemical_list: D004791:Enzyme Inhibitors; D020032:Tyrphostins; C095512:alpha-cyano-(3,4-dihydroxy)-N-benzylcinnamide; D011374:Progesterone; D000324:Adrenocorticotropic Hormone; D011388:Prolactin; C507927:Jak2 protein, rat; D053614:Janus Kinase 2; D003345:Corticosterone