Fasting and Food-stimulated Serum Gastrin Concentrations in Relation to the Antral G-cell Population

The fasting serum concentration and the first-hour serum gastric response to a protein-rich meal were related to the antral G-cell population in 14 patients with peptic ulcer. They were divided into a uremic (n=5) and non-uremic group (n=9). Fasting serum gastrin correlated significantly with the total antral G-cell mass only in the non-uremic patients who showed a relatively narrow transitional body-antrum zone. Conversely, the integrated serum gastric response was inversely related to the size of this zone in both groups of patients. A presumptive endocrine G-cell mass was estimated by subtracting the G cells in the transitional zone from the total antral G-cell population. Total gastrin output correlated positively with this estimated mass in the non-uremic group and in the material as a whole. Also, the integrated gastrin response was positively correlated with the presumptive endocrine G-cell mass in the whole material. It was concluded that G cells in the transitional body-antrum zone, where also parietal cells are present, do not release gastrin into the circulation during meal stimulation like G cells in the remaining part of the pyloric antrum. On the basis of these results and our previous morphological observations (19), we propose that the G cells in the transitional zone are involved in a paracrine interrelationship with the surrounding parietal cells rather than contributing to the circulating pool of gastrin.