Stimulation of pepsinogen release from isolated gastric glands by cholecystokininlike peptides

Gastric glands isolated from rabbit stomach were employed to study the regulation of pepsinogen secretion by peptide hormones. Cholecystokinin octapeptide (CCK-OP) stimulated pepsinogen secretion with an ED sub(50) of about 1 nM. Caerulein was as effective as CCK-OP but less potent (ED sub(50), 10 nM). Gastrin (HG-17) was found to be a weak stimulus, being only about 20% as effective as CCK-OP or caerulein. Sulfation of CCK-OP and caerulein was found to be important for potency but did not alter efficacy. The results indicate that gastric glands contain at least two peptide receptors distinguishable by sensitivity to dibytyryl cGMP. The peptide receptor associated with pepsinogen secretion appears to be selective for CCK relative to gastrin.