Figure 3. The effect of pharmacologic modulation of AMPK phosphorylation on the expressions of the incretin receptors.

A)–C) Isolated islets were treated for 24 h with vehicle (Veh; DMSO) or the AMPK inhibitor (AMPKi; 40 µM compound C) in the presence of 2.8 mM glucose. A) Total islet extracts from the isolated islets were subjected to immunoblotting for p-AMPKα (Thr¹⁷²) and AMPKα (n = 3). Data shown are representative of three independent experiments. B) The GLP-1 and GIP receptor expressions were determined by real-time quantitative RT-PCR and normalized to the expression level of β actin mRNA and normalized to the vehicle-treated samples (n = 4–7). C) Insulin secretion by the islets treated with the AMPK inhibitor or vehicle (ctl) in the presence of 2.8 mM glucose for 24 h with or without addition of 10 nM GLP-1 or 10 nM GIP. The results are expressed in ng of insulin/10 islets/90 min (n = 3). *P<0.05 and ** P<0.01.