title: Glucocorticoids modulate human brown adipose tissue thermogenesis in vivo.
abstract: BACKGROUND
  Brown adipose tissue (BAT) is a thermogenic organ with substantial metabolic capacity and has important roles in the maintenance of body weight and metabolism. Regulation of BAT is primarily mediated through the β-adrenoceptor (β-AR) pathway. The in vivo endocrine regulation of this pathway in humans is unknown. The objective of our study was to assess the in vivo BAT temperature responses to acute glucocorticoid administration.
  
  
  METHODS
  We studied 8 healthy male volunteers, not pre-selected for BAT presence or activity and without prior BAT cold-activation, on two occasions, following an infusion with hydrocortisone (0.2mg.kg-1.min-1for 14h) and saline, respectively. Infusions were given in a randomized double-blind order. They underwent assessment of supraclavicular BAT temperature using infrared thermography following a mixed meal, and during β-AR stimulation with isoprenaline (25ng.kg fat-free mass-1.min-1for 60min) in the fasting state.
  
  
  RESULTS
  During hydrocortisone infusion, BAT temperature increased both under fasting basal conditions and during β-AR stimulation. We observed a BAT temperature threshold, which was not exceeded despite maximal β-AR activation. We conclude that BAT thermogenesis is present in humans under near-normal conditions. Glucocorticoids modulate BAT function, representing important physiological endocrine regulation of body temperature at times of acute stress.
authors.affiliation: Division of Child Health, Obstetrics & Gynaecology, School of Medicine, University of Nottingham, Nottingham, NG7 2UH, UK.
authors.forename: Hannah
authors.initials: H
authors.lastname: Scotney
authors.affiliation: Division of Child Health, Obstetrics & Gynaecology, School of Medicine, University of Nottingham, Nottingham, NG7 2UH, UK; Nottingham Digestive Diseases Biomedical Research Unit, Queens Medical Centre Campus, Nottingham, NG7 2UH.
authors.forename: Michael E
authors.initials: ME
authors.lastname: Symonds
authors.affiliation: Division of Child Health, Obstetrics & Gynaecology, School of Medicine, University of Nottingham, Nottingham, NG7 2UH, UK.
authors.forename: James
authors.initials: J
authors.lastname: Law
authors.affiliation: Division of Child Health, Obstetrics & Gynaecology, School of Medicine, University of Nottingham, Nottingham, NG7 2UH, UK.
authors.forename: Helen
authors.initials: H
authors.lastname: Budge
authors.affiliation: Division of Child Health, Obstetrics & Gynaecology, School of Medicine, University of Nottingham, Nottingham, NG7 2UH, UK.
authors.forename: Don
authors.initials: D
authors.lastname: Sharkey
authors.affiliation: Institute of Metabolism and Systems Research, University of Birmingham, Birmingham, B15 2TT, UK; Centre for Endocrinology, Diabetes and Metabolism, Birmingham Health Partners, Birmingham, B15 2TT, UK. Electronic address: k.manolopoulos@bham.ac.uk.
authors.forename: Konstantinos N
authors.initials: KN
authors.lastname: Manolopoulos
mesh_terms: D002001:Adipose Tissue, Brown / Q000502:physiology*; D000293:Adolescent; D000328:Adult; D000818:Animals; D001831:Body Temperature / Q000187:drug effects; D004311:Double-Blind Method; D005938:Glucocorticoids / Q000008:administration & dosage* / Q000502:physiology; D006801:Humans; D007545:Isoproterenol / Q000494:pharmacology; D008297:Male; D011943:Receptors, Adrenergic, beta / Q000187:drug effects / Q000378:metabolism; D022722:Thermogenesis / Q000187:drug effects*; D013817:Thermography; D055815:Young Adult
chemical_list: D005938:Glucocorticoids; D011943:Receptors, Adrenergic, beta; D007545:Isoproterenol
keywords: Beta adrenoceptor; Brown adipose tissue; Glucocorticoids; Humans; Infrared thermography