The meaning of a gastrin response to a test meal.

Factors that may influence the magnitude of the gastrin response to a test meal have been examined in vitro by use of isolated sheets of antral mucosa obtained from 78 patients who underwent gastric resection. The amount of immunoreactive gastrin (IG) released during stimulation with the luminal pH at 7.4 increased linearly with the passage of time and stopped abruptly when the luminal pH was lowered to 2.5. The rate at which IG was released by the same stimulus at pH 7.4 was linearly related to the IG content in antral tissue (r = 0.66). The IG content in antral tissue increased during stimulation in vitro (10.05 +/- 2.09 to 19.77 +/- 3.38 pmol/mg tissue protein, P less than 0.03). These in vitro data suggest that the magnitude of the gastrin response to a test meal may be indicative of the IG content in antral tissue provided that: the tissue is in an unstimulated state when the stimulus is applied; the stimulus is applied for a standard span of time; the stimulus is applied to the antrum alone; and the inhibitory effects of acid are prevented by clamping the intraluminal pH at 7.4.