OXM dose-dependently increases intracellular cAMP levels in neural cells. A, The GCGR protein is present in SH-SY5Y and #9 cells as detected by Western blotting; B, Intracellular cAMP levels were marginally elevated and showed a trend of increase in SH-SY5Y cells treated with increasing doses of OXM for 15 min. P=0.06 for the highest concentration of OXM (10-7 M); C, Intracellular cAMP levels were significantly elevated in #9 cells (SH-SY5Y cells that stably over-expresses the hGLP-1R) treated with increasing concentrations (0, 10-9, 10-8, 10-7 M) of OXM for 15 min; D, Western blot analysis indicated that the pCREB/CREB ratio increased 2-fold after 15 min treatment with 10-7M OXM in SH-SY5Y cells (statistical comparison vs. control value, *P < 0.05; **P <0.01; ***P < 0.001).