Potentiation of the Gastric Secretory Response to Sham Feeding in Dogs by Infusions of Gastrin and Pentagastrin¹

The gastric acid secretory response to sham feeding in dogs provided with esophagostomies and Pavlov pouches was related to the length of the sham feeding period. In antrectomized dogs the response even to prolonged sham feeding (30 min) was small. When a small supra‐threshold dose (0.30 μg/kg/h) of synthetic human gastrin I or pentagastrin was infused, these dogs responded markedly to a short period of sham feeding (1 min), When the sham feeding period was prolonged to 10 min subthreshold amounts of gastrin and pentagastrin (0.06 μg/kg/h or less) sufficed to enhance the sham feeding response. The enhancement fulfilled the criterion proposed by Gaddum for true potentiation. The pepsin output was also increased when the sham feeding period was prolonged. In the antrectomized dogs pepsin output after sham feeding was not significantly changed when the dose of gastrin infused was increased from 0.06 to 0.30 μg/kg/h or when the dose of pentagastrin was increased from 0.30 to 1.20 μg/kg/h.