beta-Adrenergic regulation of proinflammatory cytokines in humans
Mohamed-Ali, V.; Bulmer, K.; Clarke, D.; Goodrick, S.; Coppack, S.W.; Pinkney, J.H.
International Journal of Obesity and Related Metabolic Disorders Journal of the International Association for the Study of Obesity 24(Suppl): S154-S155
2000
ISSN/ISBN: 0307-0565 PMID: 10997642 Document Number: 514516
Objectives: To investigate the effects of beta-adrenergic stimulation on IL-6 secretion in humans, and to determine the potential contribution to this response of adipocytes and peripheral blood cells (PBC). Design: Experimental study in 8 human volunteers, and in vitro studies on murine adipocyte cell-line, 3T3.L1 and 3T3.F442A, and human PBC. Measurements: Plasma IL-6 and TNFalpha responses to isoprenaline infusion. Cytokine secretion from differentiated adipocyte cell-lines and PBC in response to isoprenaline. Results: Plasma IL-6 levels increased ninefold (median) by 180 min (baseline median 0.51 [interquartile range 0.47-1.4] vs 180 mins 4.53 [2.58-5.69] pg ml-1, P=0.01). One hour after infusion, IL-6 levels (2.9 [1.27-3.98]) were lower than at 180 min (P=0.05), but higher than baseline (P=0.01). TNFalpha levels were unchanged. Differentiated adipocytes incubated in isoprenaline (0-0.1 micromolar) released significantly increased amounts of IL-6 whereas no response was elicited from PBC. Conclusions: The induction of IL-6 observed in vivo may be attributed to the beta-adrenergic stimulation of IL-6 release specifically from adipocytes, as opposed to circulating blood cells.