(A) Glucagon stimulated pCREB in PH pre-treated with phosphatase inhibitor okadaic acid (200 nM OKA) for 2-hours. (B) PKA activity and (C) Western blot analysis for phospho-PKA (p-PKA) substrates and (D) cAMP levels assessed in PH treated with glucagon. Western blot analysis for pCREB and qPCR for G6pase mRNA (bottom panel) in PH treated with (E) 20 μM forskolin or (F) 200 μM 8-br-cAMP for 2-hours. (G) PDE activity assessed by 5′-AMP levels in PH isolated at 1-week following VHL disruption. (H) Glucagon-stimulated pCREB, (I) G6pase expression and (J) cAMP levels in PH pretreated with 1 μM IBMX for 1-hour. (K) Glucagon-stimulated pCREB, G6pase and Pepck (L) mRNA or (M) protein expression (glucagon treatment for 6-hours) in PH pretreated for 16-hours with Rolipram (Rp, 1 μM), Glaucine (Gl, 1 μM), Ibudilast (Ib, 1 μM), and CP80,633 (Cp, 1 μM). PH were treated again with respective PDE inhibitors 30 minutes before glucagon treatment. Experiment with PH were done in triplicates and repeated at least twice. Each bar represents the mean value ± S.E.M. *p < 0.05, **p < 0.05, ***p < 0.001 compared to VhlF/F. # p < 0.05, ###p < 0.001, ####p < 0.0001 compared to Vehicle, $p < 0.05, $$$p < 0.001 are IBMX treated compared to their untreated controls. ^^^p < 0.001 compared to no inhibitor treatment.