Figure 7.

Induction of cAMP upregulation and CREB activation by exendin-4. (A) cAMP levels in the vehicle and exendin-4 groups. (B) Photomicrographs of pCREB in the vehicle (a) and exendin-4 (b) groups at 24 hours after reperfusion. Bar=50 μm. (c) Number of pCREB-positive cells in the ischemic boundary zone. (C) (a) Immunoblot analysis of pCREB and CREB. Equal protein loading was confirmed by measuring α-tubulin. Veh, vehicle group. (b) Densitometric analysis of pCREB protein. Data are mean±s.e.m. of three mice (Panels A and C) and five mice (panel B) in each group. ^*P<0.05, ^**P<0.001, compared with the vehicle group. cAMP, cyclic AMP; Ex-4, exendin-4; pCREB, phosphorylated cyclic AMP (cAMP) response element-binding protein.