Fig. 1.

Chronic ethanol feeding decreased β-adrenergic receptor-stimulated lipolysis in adipocytes isolated from epididymal fat. A, Adipocytes isolated from pair- and ethanol-fed rats were treated with or without increasing concentrations of isoproterenol. Basal lipolysis, measured as glycerol release over 1 h, did not differ in adipocytes from pair-fed (0.13 ± 0.02 μmol/10⁶ cells; n = 8) and ethanol-fed (0.14 ± 0.02 μmol/10⁶ cells; n = 8) rats. Values are the increase in glycerol release in response to isoproterenol over basal. Values represent means ± sem (n = 3) and were graphed using non-linear regression. B, Lipolysis in adipocytes was measured as described in Materials and Methods except that adenosine was included in the digestion and washing steps during adipocyte isolation. Adipocytes were treated with or without 1 μm isoproterenol in the presence of ADA (0.4 U/ml) and R-PIA (an A1 receptor agonist, 10 nm). Values are the increase in glycerol release in response to isoproterenol over release in the presence of ADA and R-PIA, and represent means ± sem (n = 4). *,P < 0.05, pair-fed vs. EtOH-fed. Iso, Isoproterenol; EtOH, ethanol.