title: Light activates the adrenal gland: timing of gene expression and glucocorticoid release.
abstract: Light is a powerful synchronizer of the circadian rhythms, and bright light therapy is known to improve metabolic and hormonal status of circadian rhythm sleep disorders, although its mechanism is poorly understood. In the present study, we revealed that light induces gene expression in the adrenal gland via the suprachiasmatic nucleus (SCN)-sympathetic nervous system. Moreover, this gene expression accompanies the surge of plasma and brain corticosterone levels without accompanying activation of the hypothalamo-adenohypophysial axis. The abolishment after SCN lesioning, and the day-night difference of light-induced adrenal gene expression and corticosterone release, clearly indicate that this phenomenon is closely linked to the circadian clock. The magnitude of corticostereone response is dose dependently correlated with the light intensity. The light-induced clock-dependent secretion of glucocorticoids adjusts cellular metabolisms to the new light-on environment.
authors.affiliation: Division of Molecular Brain Science, Department of Brain Science, Kobe University Graduate School of Medicine, Kobe, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Ishida
authors.forename: Tatsushi
authors.initials: T
authors.lastname: Mutoh
authors.forename: Tomoko
authors.initials: T
authors.lastname: Ueyama
authors.forename: Hideki
authors.initials: H
authors.lastname: Bando
authors.forename: Satoru
authors.initials: S
authors.lastname: Masubuchi
authors.forename: Daiichiro
authors.initials: D
authors.lastname: Nakahara
authors.forename: Gozoh
authors.initials: G
authors.lastname: Tsujimoto
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Okamura
mesh_terms: D000305:Adrenal Cortex Hormones / Q000096:biosynthesis / Q000378:metabolism*; D000311:Adrenal Glands / Q000378:metabolism* / Q000528:radiation effects*; D000818:Animals; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism; D002940:Circadian Rhythm / Q000502:physiology* / Q000528:radiation effects*; D004307:Dose-Response Relationship, Radiation; D017930:Genes, Reporter; D005938:Glucocorticoids / Q000096:biosynthesis / Q000378:metabolism*; D008027:Light; D020935:MAP Kinase Signaling System / Q000528:radiation effects; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3 / Q000378:metabolism; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism; D056950:Period Circadian Proteins; D012333:RNA, Messenger / Q000378:metabolism; D013493:Suprachiasmatic Nucleus / Q000528:radiation effects; D013564:Sympathetic Nervous System / Q000528:radiation effects; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism
chemical_list: D000305:Adrenal Cortex Hormones; D018797:Cell Cycle Proteins; D005938:Glucocorticoids; D009687:Nuclear Proteins; C539023:Per1 protein, mouse; C513312:Per2 protein, mouse; D056950:Period Circadian Proteins; D012333:RNA, Messenger; D014157:Transcription Factors; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3