Hormonal regulation of interleukin-6 production in human adipocytes.
OBJECTIVE
To elucidate the hormonal regulation of interleukin-6 (IL-6) production by human adipose tissue and its relation to leptin.


METHODS
In vitro study. Human adipocytes were incubated with dexamethasone (with or without RU486), norepinephrine and epinephrine (with or without propranolol), or insulin.


METHODS
IL-6 and leptin secretion by human adipocytes.


RESULTS
A gradual increase in IL-6 secretion by adipocytes during differentiation was observed. A positive correlation was found between basal IL-6 release and both glycerol 3-phosphate dehydrogenase activity--a marker of adipocyte differentiation-and leptin release. Dexamethasone decreased IL-6 secretion and increased leptin secretion in a dose-dependent manner. Both catecholamines increased IL-6 and leptin secretion. The effects of dexamethasone and catecholamines on IL-6 and leptin were abrogated by RU486 and propranolol, respectively. Incubation with insulin resulted in a dose-dependent stimulation of IL-6 and leptin secretion.


CONCLUSIONS
IL-6 is produced by human adipocytes and is a potential marker of adipocyte differentiation. Furthermore it is a hormonally regulated cytokine, suppressed by glucocorticoids, and stimulated by catecholamines and insulin in physiological concentrations.
Vicennati
V
V
Endocrine Unit, S. Orsola Hospital, University of Bologna, Bologna, Italy.
Vottero
A
A
Friedman
C
C
Papanicolaou
D A
DA
D017667:Adipocytes / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism*; D002454:Cell Differentiation; D002478:Cells, Cultured; D003907:Dexamethasone / Q000494:pharmacology; D004837:Epinephrine / Q000494:pharmacology; D005938:Glucocorticoids / Q000494:pharmacology; D005993:Glycerolphosphate Dehydrogenase / Q000378:metabolism; D006801:Humans; D007328:Insulin / Q000494:pharmacology; D015850:Interleukin-6 / Q000096:biosynthesis* / Q000378:metabolism; D020738:Leptin / Q000378:metabolism; D015735:Mifepristone / Q000494:pharmacology; D009638:Norepinephrine / Q000494:pharmacology; D011433:Propranolol / Q000494:pharmacology
D005938:Glucocorticoids; D007328:Insulin; D015850:Interleukin-6; D020738:Leptin; D015735:Mifepristone; D003907:Dexamethasone; D011433:Propranolol; D005993:Glycerolphosphate Dehydrogenase; D009638:Norepinephrine; D004837:Epinephrine