DEXAMETHASONE REGULATES OBESE EXPRESSION IN ISOLATED RAT ADIPOCYTES

An obese (ob) gene product, expressed specifically in adipose tissues, regulates energy balance. Here we report that adipocytes in adipose tissue actually express ob mRNA and that a synthetic glucocorticoid (dexamethasone) regulates expression of the ob gene. Addition of 100 nM dexamethasone to isolated rat adipocytes rapidly induced a 4-8 fold increase in ob mRNA. This increase in oh mRNA level was apparent within 1 h, and reached a maximum at about 7 h after stimulation. The dexamethasone-stimulated increase of ob mRNA was only partially blocked by protein synthesis inhibitors cycloheximide (20 mu g/ml) or anisomycin (200 mu M). This suggests that new protein synthesis is not necessarily required for the observed dexamethasone-stimulated increase in ob mRNA. (C) 1995 Academic Press, Inc.