Lypolytic activity (glycerol release, mg/ml) measured in adipocytes culture medium after 2 h incubation with isoproterenol or 8-Cl-cAMP. Lypolytic activity (glycerol release, mg/ml) measured in adipocytes culture medium after 2 h incubation with isoproterenol or 8-Cl-cAMP. Isoproterenol and 8-Cl-cAMP induced an increase in basal lipolytic activity in visceral (A) and subcutaneous (B) both in obese and nonobese subjects. Basal and stimulated lipolytic activity was significantly lower in visceral adipose tissue from obese patients than in samples from nonobese subjects. *P < 0.05 vs. basal; §P < 0.05 vs. nonobese. Giovanna Mantovani et al. Diabetes 2009;58:620-626 ©2009 by American Diabetes Association