Influence of diet on the development of gastrin- and somatostatin-like immunoreactivity in the stomach of rats.

The effects of changes in diet on antral gastrin-like immunoreactivities and antral and corporal somatostatin-like immunoreactivities were studied in three groups of young male rats. Group 1 rats were weaned physiologically, group 2 rats received only breast milk, and group 3 rats were fed milk until 20 days of age and then were switched abruptly to laboratory chow. In group 1, antral gastrin-like immunoreactivity and somatostatin-like immunoreactivity increased gradually from 13 days of age to adults. In group 2, antral gastrin-like immunoreactivity did not increase, and antral and corporal somatostatin-like immunoreactivity increased until 20 and 25 days of age, respectively. In group 3, there were three- to fivefold increases of antral gastrin-like immunoreactivity and somatostatin-like immunoreactivity after changing to laboratory chow. Dietary changes had no effect on the concentration of corporal somatostatin-like immunoreactivity. These results suggest that the developmental patterns of gastric gastrin-like immunoreactivity and somatostatin-like immunoreactivity are closely related to diet; laboratory chow may play an important role in the development of these gut hormones.