Effect of sympathomimetics on gastrin secretion from antral G cells in culture.

Abstract

Clinical data indicate that the control of gastrin secretion from the human antrum has a ft-adrenergic component. The purpose of the present study was to investigate whether this was due to the presence of ft-adrenergic receptors on the G cells. A newly developed short-term culture system of enriched antral G cells was used to eliminate the possibility of input from factors in the circulation and the peripheral innervation. The results demonstrated that epinephrine and terbutaline (a 2 agonist) significantly stimulated gastrin release above basal which could be blocked by the addition of propranolol (,8-adrenergic antagonist). However, the #1 agonist, dobutamine, and phenylepinephrine did not stimulate gastrin release above basal. In addition, simultaneous administration ofepinephrine and the neuropeptide, bombesin, resulted in a potentiation of gastrin release. It was concluded that the stimulatory effect of the sympathetic system on gastrin release was mediated through,#2-adrenergic receptors. The data indicated that adrenaline released from the adrenal medulla and gastrin releasing peptide (the mammalian homolog of bombesin) released from the intrinsic innervation of the stomach interact with respect to the stimulation of gastrin.

Bombesin-induced gastrin release from canine G cells is stimulated by Ca2+ but not by protein kinase C, and is enhanced by disruption of rho/cytoskeletal pathways.

“…G cells are stimulated by gastrin-releasing peptide (GRP)/bombesin (1)(2)(3). Sympathomimetics, acetylcholine, prostaglandin, adenosine, and somatostatin are other substances known to act through specific receptors on canine G cells (1,(4)(5)(6)(7). All these receptors belong to the superfamily of seven-transmembrane, G-protein-coupled receptors.…”

Regulation of parietal cell calcium signaling in gastric glands

“…Over the years, three major stimulants of acid secretion have emerged: ACh released from vagal nerve fibers within the enteric nervous system or in the vicinity of gastric epithelial cells (42), gastrin released from the G cells of the antral glands (5), and histamine released from enterochromaffin-like (ECL) cells in the fundic gland (17,31). Quite recently, pituitary adenylate cyclase-activating peptide (PACAP) has also been considered to be important in gastric acid stimulation (46).…”