Leptin expression in adipose tissue from obese humans: depot-specific regulation by insulin and dexamethasone
Russell, C.D.; Petersen, R.N.; Rao, S.P.; Ricci, M.R.; Prasad, A.; Zhang, Y.; Brolin, R.E.; Fried, S.K.
American Journal of Physiology 275(3): E507-E515
1998
ISSN/ISBN: 0002-9513 PMID: 9725819 Document Number: 492551
We investigated the in vitro regulation of leptin expression in adipose tissue from severely obese women and men before and after culture with insulin (7 nM) and/or dexamethasone (25 nM). Leptin mRNA and leptin secretion were two- to threefold higher in subcutaneous vs. omental adipose tissue before culture. Dexamethasone transiently increased leptin mRNA approximately twofold in both depots after 1 day of culture 1.5- to 3-fold in subcutaneous tissue throughout 7 days of culture (P < 0.05 vs. basal). The combination of insulin and dexamethasone increased leptin mRNA and leptin secretion approximately two- to threefold in both depots at day 1 (P < 0.005 vs. basal or insulin) and maintained leptin expression throughout 7 days of culture. We conclude that insulin and glucocorticoid have depot-specific effects and function synergistically as long-term regulators of leptin expression in omental and subcutaneous adipose tissue from obese subjects. Reprinted by permission of the publisher.