Effect of food deprivation on rat gastric somatostatin and gastrin release.

The influence of food deprivation on the release of somatostatin and gastrin from the rat stomach was investigated using an isolated, vascularly perfused rat stomach preparation. Basal and acetylcholine-stimulated gastrin release were significantly lower after a 3 day starvation, whereas the inhibitory effect of acetylcholine and the stimulatory effect of glucagon on somatostatin secretion were not influenced by fasting. In dose-response studies, isoproterenol dose-dependently stimulated somatostatin secretion. The increases were similar in both groups fasted for 12 and 72 h. Gastrin release remained at basal levels. Bombesin dose-dependently increased gastrin secretion; this stimulatory effect on the G cell was significantly reduced after a 72-h starvation. Somatostatin secretion was only weakly stimulated by high concentration of bombesin revealing no effect of fasting. Somatostatin content of the nonperfused stomach declined from 57 +/- 4 pmol/stomach in fed controls to 36 +/- 3 pmol/stomach after a 72-h fast. Antral gastrin concentration decreased by 42% in a 3-day fasting period. It is concluded that rat gastric somatostatin release in vitro is--in contrast to gastrin--not altered by food deprivation while the somatostatin content in gastric tissue declined during fasting.