Adrenergic and cholinergic interactions in rat gastric somatostatin and gastrin release

The interactions of adrenergic and cholinergic influences on the gastric D cell were studied using an isolated perfused rat stomach in vitro. The sevenfold increase in the release of somatostatin-like immunoreactivity (SLI) in response to isoproterenol (4 . 10(-8) M) was dose-dependently inhibited by acetylcholine (10(-5) to 10(-8) M) whereas gastrin levels increased in a dose-dependent manner. Both inhibition of stimulated SLI and augmentation of gastrin release were completely abolished by atropine (10(-6) M). Isoproterenol (8 . 10(-9) M)-induced stimulation of SLI secretion was not altered by atropine. Antral exclusion completely eliminated gastrin secretion but basal and beta-adrenergic stimulated SLI release was not influenced. It is concluded that (1) cholinergic agonism reverses the stimulatory action of adrenergic agonists on the D cell, and (2) SLI from the rat stomach in vitro originates almost exclusively in the fundic region.