EFFECT OF VAGAL INNERVATION ON ACID AND PEPSIN RESPONSE TO HISTAMINE AND GASTRIN

The acid and pepsin responses to a wide range of doses of gastrin extract and of histamine were determined in dogs that had both a fistula of the vagally innervated main stomach (GF) and a vagally denervated Heidenhain pouch (HP). The GFs gave the same maximal acid response with gastrin as with histamine whereas the maximal acid response of the HPs to gastrin was only 45% of that to histamine. Opening the GF increased the response of the HP to submaximal doses of gastrin and, to a lesser extent, of histamine. With the GF open, peak rates of secretion from the HP were not sustained, particularly with gastrin stimulation. Sustained increase in pepsin output over basal levels occurred in GFs with very low doses of gastrin but not with any dose of histamine and in HPs with all doses of histamine and of gastrin tested. In both GFs and HPs doses of histamine that were supramaximal for acid secretion suppressed pepsin secretion without a concomitant fall in acid secretion, a phenomenon not seen with stimulation with gastrin.