Depletion of antral gastrin after food in rats.

The results of these studies indicate that in fasting rats, there is an abrupt and prolonged rise in circulating gastrin after feeding. This increase in serum gastrin is accompanied by an early (five minutes) diminution in antral gastrin which is followed by slightly higher and more variable antral gastrin values. These findings suggest that feeding triggers the release of gastrin with early depletion of antral gastrin and that, subsequently, gastrin syhthesis and release interact cyclically to maintain antral and serum concentrations of gastrin. Antral, fundic, and duodenal gastrin values in rats are similar to those reported in dogs and cats. The jejunum of the rat contains little, if any, gastrin.