Russell C D, Petersen R N, Rao S P, Ricci M R, Prasad A, Zhang Y, Brolin R E, Fried S K
Department of Nutritional Sciences, Rutgers, The State University of New Jersey, New Brunswick, New Jersey 08901, USA.
Am J Physiol. 1998 Sep;275(3):E507-15. doi: 10.1152/ajpendo.1998.275.3.E507.
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 [P < 0.01 vs. basal (no hormone control)], but leptin secretion was only increased in omental adipose tissue (P < 0.005 vs. basal). Insulin did not increase leptin mRNA in either depot but increased leptin secretion approximately 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.
我们研究了重度肥胖女性和男性脂肪组织中瘦素表达的体外调节情况，这些脂肪组织在分别用胰岛素（7 nM）和/或地塞米松（25 nM）培养前后进行检测。培养前，皮下脂肪组织中的瘦素mRNA和瘦素分泌水平比网膜脂肪组织高两到三倍。培养1天后，地塞米松使两个部位的瘦素mRNA瞬时增加约两倍[与基础水平（无激素对照）相比，P < 0.01]，但瘦素分泌仅在网膜脂肪组织中增加（与基础水平相比，P < 0.005）。胰岛素在两个部位均未增加瘦素mRNA，但在整个7天的培养过程中，皮下组织中的瘦素分泌增加了约1.5至3倍（与基础水平相比，P < 0.05）。胰岛素和地塞米松联合使用在第1天时使两个部位的瘦素mRNA和瘦素分泌增加了约两到三倍（与基础水平或胰岛素相比，P < 0.005），并在整个7天的培养过程中维持瘦素表达。我们得出结论，胰岛素和糖皮质激素具有特定部位的作用，并且作为肥胖受试者网膜和皮下脂肪组织中瘦素表达的长期调节因子发挥协同作用。
