title: Short-term beta-adrenergic regulation of leptin, adiponectin and interleukin-6 secretion in vivo in lean and obese subjects.
abstract: OBJECTIVE
  Adipose tissue and skeletal muscle are endocrine organs, secreting substances that have been implicated in obesity-related disorders. This study examined short-term beta-adrenergic regulation of circulating leptin, adiponectin and interleukin-6 (IL-6) concentrations and secretion from abdominal subcutaneous adipose tissue and muscle (IL-6) in vivo in lean and obese subjects.
  
  
  METHODS
  Systemic concentrations and net fluxes of leptin, adiponectin and IL-6 across abdominal subcutaneous adipose tissue and forearm skeletal muscle (IL-6) were assessed before and during beta-adrenergic stimulation (intravenous isoprenaline infusion) in 13 lean and 10 obese men.
  
  
  RESULTS
  Basal circulating leptin concentrations were higher in the obese (p < 0.001), while circulating adiponectin (p = 0.45) and IL-6 concentrations (p = 0.41) were not different between groups. beta-Adrenergic stimulation decreased leptin concentrations in both groups (p < 0.01), but did not reduce net abdominal subcutaneous adipose tissue leptin release. Increased leptin clearance and/or decreased leptin secretion from other fat depots may explain the reduction in leptin concentrations. Adiponectin concentrations remained unchanged during beta-adrenergic stimulation in both groups. beta-Adrenergic stimulation increased IL-6 concentration, which was more pronounced in the obese (p = 0.01 vs. lean). This cannot be explained by increased IL-6 release per unit abdominal subcutaneous adipose tissue and muscle but might be because of the increased fat mass and fat-free mass at whole-body level.
  
  
  CONCLUSIONS
  Short-term beta-adrenergic stimulation decreases leptin concentrations, which cannot be explained by reduced net leptin release from abdominal subcutaneous adipose tissue, while it elevates IL-6 concentration partly by increased release from this fat depot and muscle. Finally, beta-adrenergic stimulation has no short-term regulatory role in adiponectin secretion.
authors.affiliation: Department of Human Biology, Nutrition and Toxicology Research Institute Maastricht (NUTRIM), Maastricht University, Maastricht, The Netherlands. g.goossens@hb.unimaas.nl
authors.forename: G H
authors.initials: GH
authors.lastname: Goossens
authors.forename: J W E
authors.initials: JW
authors.lastname: Jocken
authors.forename: M A
authors.initials: MA
authors.lastname: van Baak
authors.forename: E H J M
authors.initials: EH
authors.lastname: Jansen
authors.forename: W H M
authors.initials: WH
authors.lastname: Saris
authors.forename: E E
authors.initials: EE
authors.lastname: Blaak
mesh_terms: D052242:Adiponectin / Q000097:blood / Q000378:metabolism*; D000318:Adrenergic beta-Agonists / Q000494:pharmacology*; D000328:Adult; D016022:Case-Control Studies; D005542:Forearm; D006801:Humans; D015850:Interleukin-6 / Q000097:blood / Q000378:metabolism*; D007545:Isoproterenol / Q000494:pharmacology*; D020738:Leptin / Q000097:blood / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000378:metabolism; D009765:Obesity / Q000097:blood / Q000503:physiopathology*; D018709:Statistics, Nonparametric; D013268:Stimulation, Chemical; D050507:Subcutaneous Fat, Abdominal / Q000378:metabolism
chemical_list: D052242:Adiponectin; D000318:Adrenergic beta-Agonists; D015850:Interleukin-6; D020738:Leptin; D007545:Isoproterenol