title: The differential effect of food intake and beta-adrenergic stimulation on adipose-derived hormones and cytokines in man.
abstract: We determined whether the physiologic changes that accompany food intake or sympathetic activation by beta-adrenergic stimulation result in alterations in the secretion of leptin, tumor necrosis factor-alpha (TNF alpha), or interleukin-6 (IL-6) by serially sampling sc abdominal adipose interstitial fluid by open-flow microperfusion before and after a standardized meal and in response to isoproterenol (1 micromol/L) delivered locally. Post cibum IL-6 rose up to 5-fold, whereas leptin and TNF alpha secretion did not change; TNF alpha, but not IL-6, correlated positively with indices of lipolysis. Isoproterenol-induced lipolysis was accompanied by a transient 40% reduction in leptin and a parallel 85% elevation of TNF alpha concentration, whereas IL-6 levels did not change; again, TNF alpha correlated positively with lipolysis. These data show that secretion of some, but not all, metabolically relevant polypeptides by adipose tissue is modulated within a short time frame by food or stress stimuli, suggesting a role of these peptides in local autocrine/paracrine or distant endocrine effects on fat metabolism. TNF alpha's close correlation with lipolysis suggests that this cytokine participates in a local positive autocrine feedback loop, potentiating lipolysis and inhibiting insulin's antilipolytic actions. The regulations of adipose leptin, TNF alpha, and IL-6 secretion seem distinct from each other and different in the fed vs. fasting state.
authors.affiliation: Developmental Endocrinology Branch, National Institute of Child Health and Human Development, Bethesda, Maryland 20892-1862, USA. orbanz@cc1.nichd.nih.gov
authors.forename: Z
authors.initials: Z
authors.lastname: Orban
authors.forename: A T
authors.initials: AT
authors.lastname: Remaley
authors.forename: M
authors.initials: M
authors.lastname: Sampson
authors.forename: Z
authors.initials: Z
authors.lastname: Trajanoski
authors.forename: G P
authors.initials: GP
authors.lastname: Chrousos
mesh_terms: D000273:Adipose Tissue / Q000187:drug effects / Q000378:metabolism*; D000318:Adrenergic beta-Agonists / Q000494:pharmacology*; D000328:Adult; D016207:Cytokines / Q000378:metabolism*; D004435:Eating / Q000502:physiology*; D005215:Fasting; D005260:Female; D006728:Hormones / Q000378:metabolism*; D006801:Humans; D015850:Interleukin-6 / Q000097:blood; D007545:Isoproterenol / Q000494:pharmacology; D020738:Leptin; D008066:Lipolysis / Q000187:drug effects; D008297:Male; D019518:Postprandial Period; D011506:Proteins / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
chemical_list: D000318:Adrenergic beta-Agonists; D016207:Cytokines; D006728:Hormones; D015850:Interleukin-6; D020738:Leptin; D011506:Proteins; D014409:Tumor Necrosis Factor-alpha; D007545:Isoproterenol