[Psychosensory initiation of gastric secretion in dogs. Inter-relation of vagal component, gastrin, histamine and somatostatin].

The effects of vagal stimulation on gastric secretion and on blood gastrin, histamine and somatostatin release have been assessed in three esophagostomized dogs equipped with gastric fistula and Heidenhain pouch. The animals were submitted to sham feeding of variable duration (from 2.5 to 12.5 min) and composition. In response to standard composition of the sham feeding, acid and pepsin responses were observed in the gastric fistula only; they were closely related to the sham feeding duration. Integrated histamine responses were also closely related to sham feeding duration and were correlated with acid or pepsin responses. Gastrin was released by sham feeding induced-vagal stimulation, but there were no relationship between gastrin and secretory responses. Somatostatin release decreased as duration of sham feeding stimulation increased and correlated negatively with acid or pepsin responses. Modified standard sham feeding, by adding either lipids or glucids resulted in the same gastric and hormonal responses as standard sham feeding. It appears that 1 degree) vagal stimulation resulting in the psychosensorial receptors stimulation can be quantified, 2 degrees) histamine reduces somatostatin release and could represent a non cholinergic vagal mediator, capable of controlling somatostatin release in the cephalic phase of gastric secretion.