Figure 4. Rolipram increases level of phosphor-AMPK via CaMKKβ. (A-B) Time courses of the effects of db-cAMP and rolipram on phospho-AMPK levels in C2C12 cells. (C-D) Phospho-AMPK levels in cells treated with a PKA or CaMKKβ inhibitor. (E-F) Phospho-AMPK levels in cells treated with a SIRT1 inhibitor or expression SIRT6 siRNA.