Autonomic Nervous Control of Fundic Secretion of Somatostatin and Antral Secretion of Gastrin and Somatostatin in Pigs

Abstract

By selective catheterization of gastric veins, we studied the secretion of gastrin and somatostatin from the antrum and of somatostatin from the gastric fundus-corpus region in anaesthetized pigs with or without acute adrenalectomy. The secretion was studied during electrical stimulation of the vagus nerves and the splanchnic nerves and simultaneous irrigation of gastric lumen with fluids of high, low, and neutral pH. The corpus-fundus somatostatin response to vagal stimulation was biphasic with a short-lasting initial increase followed by a lasting inhibition, which was little influenced by intraluminal pH or adrenalectomy. In pigs with intact adrenals, antral somatostatin secretion was increased by vagal stimulation, whereas in adrenalectomized pigs, the effect was inhibitory. The vagally induced inhibition was abolished when the intragastric pH was kept at pH 2. The antral gastrin secretion was strongly stimulated by vagal stimulation. The magnitude of the secretory response was inversely related to the pre-stimulatory somatostatin levels, but not to the nerve stimulation responses. Splanchnic stimulation increased arterial blood pressure and gastric blood flow, but had inconsistent effects on somatostatin and gastrin secretion.

Muscarinic Regulation of Somatostatin Release from Primary Cultures of Human Antral Epithelial Cells

“…25], Therefore this output could mask effects on antral secretion. In the pig separate sampling of blood from the right (antral) and left (corpus/fundus) gastro-epiploic veins for SS-IR demonstrated that the effect of vagal stimulation resulted in an increased release from the antrum and an inhibition of basal levels from the corpus/fundus [10], The au thors concluded that the effect of vagal stimu 38 Buchan/MacLeod/Meloche/Kwck Muscarinic Receptors and Somatostatin Secretion lation on SS-IR release from the stomach was region-specific. The differential regulation of SS-IR release may be species-specific because in studies of segments of either antral or fundic mucosa from the rat stomach the inhibi tory response to methacholine was identical [81-In similar primary cell cultures derived from canine oxyntic mucosa.…”

“…The majority of this work has involved the use of isolated, perfused, whole stomach preparations in the rat [6][7][8], dog [9], and pig [10], although isolated gastric glands [11] and segments of antral and fundic mucosa [12] have also been investigated. These studies were in general agreement that the release of somatostatin-immunoreactivity (SS-1R) from the stomach was inhibited by parasympathetic receptor activation.…”

Cell-specific Processing of Chromogranin A in Endocrine Cells of the Rat Stomach

“…Antiserum R36D8 (raised against CgA 124-144 ) immunostained EC cells and D cells but not G cells. The fact that the D cells of both the oxyntic mucosa (closed type) and the antrum (open type) displayed identical patterns of CgA immunostaining is notable in view of the fact that they appear to differ from each other both morphologically and functionally (Alumets et al 1979;Olesen et al 1987).…”