III.4.A. Gastrin

Its production is stimulated by peptides and amino acids in the stomach.

Its effects (Fig. 12):

• release of hydrochloric acid (HCl) from parietal cells in the stomach ↑,
• histamine release from enterochromaffin cells in the stomach ↑,
• Pylorus motility ↑,
• ileum motility ↑,
• gastric mucosa proliferation ↑,
• gastric pepsin secretion ↑.

It is stimulated by GRP, N and ACTH (through Somatostatin inhibition).

It is inhibited by Somatostatin, secretin, GIP, VIP and acids.

Figure 12. The regulation of gastrin release

(GRP = gastrin-releasing peptide, Ach = acetylcholine, ACTH = adrenocorticotropic hormone, N = norepinephrine, VIP = vasoactive intestinal polypeptide, GIP = gastric inhibitory peptide;
red arrow = inhibition, green arrow = stimulation)