In vitro gastrin secretion by rat antrum: effects of neurotransmitter agonists, antagonists, and modulators of secretion.

Gastrin release was studied from rat antral mucosal cells maintained under tissue culture conditions. Results of experiments with neurotransmitter agonists, antagonists, and modulators indicate the following: Adrenergic mediation of gastrin release occurs in vitro. Adrenergic stimulatory action could be demonstrated by norepinephrine and, more specifically, beta-receptor activators, whereas an alpha-receptor activator was inhibitory. The effects appear to be specific because the agonists stimulate gastrin release at low concentrations and because these effects are blocked by the appropriate antagonists. Because high carbachol concentrations were needed to produce gastrin secretion, and inhibition by atropine occurred also at high concentrations, these effects may be nonspecific. Both carbachol- and norepinephrine-mediated gastrin release are modified by somatostatin and adenosine. Effective modulation of gastrin release by these substances may be relevant in understanding the fine regulation of gastrin release during digestive processes.