Cholecystokinin and Gastrin Inhibit Histamine Stimulated Aminopyrine Uptake in Isolated Rabbit Gastric Glands

Abstract

In the present study we have analyzed if cholecystokinin (CCK) or gastrin (G) can inhibit acid production in isolated rabbit gastric glands as revealed by the aminopyrine technique.

The results show that G 17 I, CCK 8 NS, CCK 8 S, ceruletide and CCK 39 significantly inhibit histamine induced aminopyrine accumulation. No significant inhibition was noted for G 4, G 34 and NT G 1–13. As a group the CCK peptides were more effective than the gastrin peptides in inhibiting the aminopyrine uptake. CCK 8 S and ceruletide, the most potent inhibitors, reduced histamine induced aminopyrine accumulation with an ED₅₀ of 10⁻⁹ and 10⁻¹⁰ M respectively. These potencies are similar to those by which CCK peptides stimulate isolated pancreatic acini to secrete amylase. Inhibition evoked by CCK 8 S was most effective following 20–40 min of incubation time, possibly indicating that the effect is mediated by the release of an intermediate substance.

The results may therefore indicate a role for cholecystokinin as a physiological inhibitor of acid secretion in the rabbit. The results may also contribute to explain why the potent gastric secretagogue gastrin per se fails to stimulate acid formation in gastric glands isolated from the rabbit.