title: Effects of orexin on cultured porcine adrenal medullary and cortex cells.
abstract: New orexigenic peptides called orexins have recently been described in the neurons of the lateral hypothalamus and perifornical area. No orexins have been found in the adipose tissues or visceral organs, including the adrenal gland. However, expression of the orexin receptor (OXR) in the rat adrenal gland has been reported. With regard to the effects of orexins on peripheral organs, we previously reported that orexins suppress catecholamine synthesis and secretion in the rat pheochromocytoma cell line PC12. To further clarify the pharmacological effects of orexins on peripheral organs, we examined the effects of orexin-A on catecholamine, cortisol, and aldosterone secretion, using cultured porcine adrenal glands. We initially confirmed the expression of the orexin receptor (OXR-1) in cultured porcine adrenal medulla and cortex. Orexin-A (1000 nM) significantly increased the release of both epinephrine (E) and norepinephrine (NE) from porcine adrenal medullary cells. Similarly, orexin-A (> or = 100 nM) significantly increased the release of both cortisol and aldosterone from porcine adrenal cortex cells. Orexin-A (100 nM) significantly inhibited basal and the PACAP-induced increase in cAMP levels in adrenal medullary cells. Conversely, orexin-A (>o = 100 nM) significantly increased the cAMP level in adrenal cortex cells. These results indicate that orexin-A induces the release of catecholamine from porcine adrenal medullary cells, and aldosterone and cortisol from the cortex cells and has opposite effects on cAMP levels in adrenal medulla and cortex.
authors.affiliation: Department of Clinical Pathology, Institute of Clinical Medicine, University of Tsukuba, 1-1-1 Tenoudai, lbaraki 305-8575, Tsukuba, Japan.
authors.forename: Toru
authors.initials: T
authors.lastname: Nanmoku
authors.forename: Kazumasa
authors.initials: K
authors.lastname: Isobe
authors.forename: Takeshi
authors.initials: T
authors.lastname: Sakurai
authors.forename: Akihiro
authors.initials: A
authors.lastname: Yamanaka
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Takekoshi
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Kawakami
authors.forename: Katsutoshi
authors.initials: K
authors.lastname: Goto
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Nakai
mesh_terms: D000302:Adrenal Cortex / Q000187:drug effects* / Q000378:metabolism; D000313:Adrenal Medulla / Q000187:drug effects* / Q000378:metabolism; D000450:Aldosterone / Q000378:metabolism; D000818:Animals; D002352:Carrier Proteins / Q000494:pharmacology*; D002395:Catecholamines / Q000378:metabolism; D002478:Cells, Cultured; D000242:Cyclic AMP / Q000096:biosynthesis; D006152:Cyclic GMP / Q000096:biosynthesis; D006854:Hydrocortisone / Q000378:metabolism; D047908:Intracellular Signaling Peptides and Proteins; D009479:Neuropeptides / Q000494:pharmacology*; D064446:Orexin Receptors; D000068797:Orexins; D012333:RNA, Messenger / Q000096:biosynthesis / Q000187:drug effects; D043562:Receptors, G-Protein-Coupled; D018013:Receptors, Neuropeptide / Q000096:biosynthesis / Q000235:genetics; D013552:Swine
chemical_list: D002352:Carrier Proteins; D002395:Catecholamines; D047908:Intracellular Signaling Peptides and Proteins; D009479:Neuropeptides; D064446:Orexin Receptors; D000068797:Orexins; D012333:RNA, Messenger; D043562:Receptors, G-Protein-Coupled; D018013:Receptors, Neuropeptide; D000450:Aldosterone; D000242:Cyclic AMP; D006152:Cyclic GMP; D006854:Hydrocortisone