FIGURE 1.

Agonists that increase cAMP stimulate both lipolysis and AMPK activation. L1 adipocytes were treated with the phosphodiesterase inhibitor IBMX (0.5 mm), the β-agonist isoproterenol (Iso, 10 μm), or the adenylyl cyclase activator forskolin (FKN, 20 μm) for 1 h, following a 4-h preincubation period in serum-free DMEM containing 0.5% fatty acid-free BSA. Ctrl, control. A, activation of AMPK as assessed from immunoblots of phospho-AMPK Thr-172 and P-ACC Ser-79. IB, immunoblot. B, lipolysis was quantified on the basis of glycerol release into the incubation media. Results for glycerol release are means ± S.E. (n = 9) and were obtained in three independent experiments. Immunoblots shown are representative of those obtained in a total of nine lysates. Significantly different from control group: ^***, p < 0.001.