The glandular mucosa has many cell types with important physiologic products. The distribution and density of these cell types varies by region of the stomach and by species. Substantial differences have been found between rodents, cats, dogs, and humans. Gastrin is released into the blood by gastric G cells and reaches receptors on the parietal cell via the systemic circulation. Gastrin release is stimulated by gastric distension, protein, and increased luminal pH. Histamine is released from mast cells and enterochromaffin-like cells within the gastric gland.
Histamine is the most potent stimulus for HCl secretion.
Pepsin is highly proteolytic, and contributes to lesion formation.