title: Salivary 3-methoxy-4-hydroxyphenylglycol increases after awakening in healthy young adults.
abstract: Levels of 3-methoxy-4-hydroxyphenylglycol (MHPG) may reflect central noradrenergic activity. In this study, we investigated salivary MHPG changes after awakening, and explored their relationships with cortisol and peripheral autonomic activity. The participants were 25 college students. Saliva samples were collected on awakening and 30 min after awakening to determine MHPG and cortisol. Ambulatory electrocardiograms were obtained to assess heart rate, cardiac sympathetic index (CSI), and cardiac vagal index (CVI) before and after awakening. MHPG levels increased significantly during the first 30 min after awakening. Similarly, cortisol, heart rate, and CSI increased during the 30 min after awakening, but changes in MHPG did not correlate with changes in cortisol, heart rate, CSI, and CVI during that period. This study demonstrated that salivary MHPG levels increase after awakening, in common with cortisol, heart rate, and cardiac sympathetic activity.
authors.affiliation: Department of Epidemiology and Public Health, Graduate School of Medicine, Yokohama City University, Yokohama, Japan.
authors.forename: Nagisa
authors.initials: N
authors.lastname: Sugaya
authors.forename: Shuhei
authors.initials: S
authors.lastname: Izawa
authors.forename: Ryuichiro
authors.initials: R
authors.lastname: Yamamoto
authors.forename: Namiko
authors.initials: N
authors.lastname: Ogawa
authors.forename: Jumpei
authors.initials: J
authors.lastname: Yajima
authors.forename: Hisayoshi
authors.initials: H
authors.lastname: Okamura
authors.forename: Satoshi
authors.initials: S
authors.lastname: Horiuchi
authors.forename: Akira
authors.initials: A
authors.lastname: Tsuda
authors.forename: Shinobu
authors.initials: S
authors.lastname: Nomura
mesh_terms: D000328:Adult; D001341:Autonomic Nervous System / Q000502:physiology*; D002940:Circadian Rhythm / Q000502:physiology*; D005026:Ethylene Glycols / Q000032:analysis*; D005260:Female; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D008297:Male; D010636:Phenols / Q000032:analysis*; D012463:Saliva / Q000737:chemistry; D014630:Vagus Nerve / Q000502:physiology; D014851:Wakefulness / Q000502:physiology*; D055815:Young Adult
chemical_list: D005026:Ethylene Glycols; D010636:Phenols; C034604:4-hydroxyphenethylene glycol
keywords: Awakening; Central noradrenergic metabolism; MHPG; Saliva