Figure 1.

Glucose‐dependent insulinotropic polypeptide (GIP) secretory mechanism induced by glucose in K‐cells. Under the normoglycemic state, adenosine triphosphate‐sensitive K (K_ATP) channels in K‐cells are closed in the basal condition. On glucose loading, glucose transported through sodium‐dependent glucose transporter (SGLT1) induces membrane depolarization and GIP secretion from K‐cells. Under the hyperglycemic condition, K_ATP channels in K‐cells are open in basal condition. On glucose loading, incremental increase in ATP closes the K_ATP channel and depolarizes the membrane, generating an increase in GIP secretion in addition to the SGLT1‐dependent GIP secretion. GK, glucokinase; GLUT5, glucose transporter 5.