– PACAP (1-38) free acid TFA, an endogenous neuropeptide, effectively enhances antral motility and somatostatin secretion, while concurrently suppressing gastrin secretion and promoting the release of vasoactive intestinal polypeptide, gastrin-releasing peptide, and substance P. Additionally, it amplifies N-methyl-D-aspartate receptor function and brain-derived neurotrophic factor expression via RACK1 [1] [2].