Chronic ethanol consumption disrupts G protein-dependent signaling pathways in rat adipocytes. Since lipolysis in adipocytes is regulated by G protein-mediated cAMP signal transduction, we hypothesized that cAMP-regulated lipolysis may be vulnerable to long-term ethanol exposure. Male Wistar rats were fed a liquid diet containing ethanol as 35% of total calories or pair-fed a control diet that isocalorically substituted maltose dextrins for ethanol for 4 weeks. Lipolysis was measured by glycerol release over 1 h with or without agonists in adipocytes isolated from epididymal fat. Chronic ethanol feeding decreased -adrenergic receptor-stimulated lipolysis, but had no effect on basal lipolysis. In response to -adrenergic activation, the early peak of cAMP accumulation was suppressed after ethanol feeding, although the basal cAMP concentration in adipocytes did not differ between pair- and ethanol-fed rats. The suppression in cAMP accumulation caused by ethanol feeding was associated with increased activity of phosphodiesterase 4 (PDE4). Chronic ethanol feeding also decreased -adrenergic receptor-stimulated protein kinase A (PKA) activation and phosphorylation of its downstream proteins, perilipin A and hormone-sensitive lipase (HSL), the primary lipase mediating lipolysis. In conclusion, these data suggest that chronic ethanol feeding increased PDE4 activity in adipocytes, resulting in decreased accumulation of cAMP in response to -adrenergic activation and a suppression of -adrenergic stimulation of lipolysis.