Potent glucose-dependent insulinotropic peptide produced by post-translational processing of proglucagon in intestinal L-cells. Displays high affinity for GLP-1 receptors expressed in rat insulinoma-derived RINm5F cells (Kd = 204 pM). Stimulates insulin gene transcription and secretion in pancreatic β-cells. Displays antiapoptotic effects in hippocampal neurons and reduces food intake in fasted rats following central administration. MW (observed): 3297.67.