Answer:
Acetylcholine and GRP stimulates and increase the gastrin secretion in the stomach.
Step-by-step explanation:
Acetylcholine can acts as a neurotransmitter as well as hormone. The parasymapthetic nerves release acetylcholine that stimulates the release of gastrin secretion in the stomach and helps in the process of digestion.
Gastrin releasing peptide (GRP) acts as a regulatory molecule of the gastrin. GRP is a neuropeptide hormones that helps in the secretion of gastrin by stimulating the G cells of the stomach.
Thus, both GRP and acetylcholine stimulates the gastrin secretion.