Relationship between disposal rate of exogenous gastrin and sensitivity to stimulation of acid secretion by this hormone in dogs.

The effect of graded doses of synthetic human gastrin and pentagastrin on gastric secretion from the innervated and denervated stomach was measured in dogs. The circulating levels of gastrin during the infusion of this hormone were also estimated. The increase in gastrinemia for a fixed dose of exogenous gastrin differed from dog to dog. The dose for half-maximal response to gastrin was negatively correlated with the observed increase in serum gastrin. This suggests that the disposal rate of gastrin influences the calculated sensitivity of the parietal cells to this hormone. In the gastric fistula and in the pouch, maximal acid responses for gastrin and pentagastrin were linearly correlated, but doses for half maximal responses were not. This indicates that step-dose infusion of pentagastrin may be used to estimate the maximal acid response to gastrin, but it is not proven that such a test is useful to estimate the sensitivity of the parietal cells to gastrin in individual dogs.