Non-gastrin, Intestinal-Phase Secretion

Four mongrel dogs were prepared with a Heidenhain pouch, a gastric fistula, and a 90-cm-long Thiry-Vella loop. After recovery, dose-reponse curves were obtained with different doses of pentagastrin, and the maximal acid output was determined. The jejunal loop was perfused for 3 h with either 5% liver extract or with 0.15 M NaCl at a rate of 114 ml/h. To verify that the stomach could release gastrin and that the assay could detect that change, antral perfusion with liver extract was performed. Serum gastrin levels and acid output were measured every 30 min. Perfusion of the jejunal loop with liver extract resulted in a significant increase in acid output from the Heidenhain pouch and the gastric fistula, whereas perfusion with saline solution failed to show any changes. The magnitude of acid response from the Heidenhain pouch and gastric fistula was 11% and 18%, respectively, as compared with maximal pentagastrin stimulation. The serum gastrin levels remained unchanged during both liver extract and saline perfusion of the jejunal loop, in contrast to the marked increase in serum gastrin level after antral perfusion. The results confirm the existence of the intestinal phase of gastric acid stimulation in dogs as an entity and show that the magnitude of this phase is significantly lower than has been suggested by results of earlier studies. Furthermore, the results suggest that the intestinal phase of gastric secretion in dogs is most probably elicited through a humoral agent other than gastrin.