Search results for "Enterochromaffin cell"
showing 10 items of 20 documents
Adrenergic modulation of the release of 5-hydroxytryptamine from the vascularly perfused ileum of the guinea-pig
1988
1. Isolated segments of the guinea-pig ileum were vascularly perfused and the release of 5-hydroxytryptamine (5-HT) and 5-hydroxyindoleacetic acid (5-HIAA) into the portal venous effluent was determined by h.p.l.c. with electrochemical detection. Test substances were applied via the arterial perfusion medium. 2. Isoprenaline (0.1 microM) increased the outflow of 5-HT and 5-HIAA maximally by about 75% and this was antagonized by propranolol (0.1 microM). Forskolin (1-10 microM) increased the outflow of 5-HT by approximately 105% and that of 5-HIAA by approximately 55%. The phosphodiesterase inhibitor AH 21-132 (0.1-1 microM) increased the outflow of 5-HT and 5-HIAA by about 70%. Isoprenaline…
Cisplatin increases the release of 5-hydroxytryptamine (5-HT) from the isolated vascularly perfused small intestine of the guinea-pig: Involvement of…
1991
Isolated segments of the guinea-pig small intestine were vascularly perfused and the release of 5-hydroxytryptamine (5-HT) and 5-hydroxyindoleacetic acid (5-HIAA) into the portal venous effluent determined by high pressure liquid chromatography with electrochemical detection. Release of acetylcholine from isolated superfused intestinal segments was determined as outflow of [3H]radioactivity from preparations preincubated with [3H]choline. Cisplatin (3 microM) increased the outflow of 5-HT and 5-HIAA by about 90%. At 30 and 100 microM cisplatin decreased the outflow of 5-HT and its metabolite by 40%-50%. The stimulatory effect of cisplatin was consistently observed only when the bicarbonate-…
Cholinergic modulation of the release of 5-hydroxytryptamine from the guinea pig ileum.
1987
Isolated segments of the guinea pig ileum were vascularly perfused and the release of 5-HT and its metabolite 5-HIAA into the portal venous effluent determined by HPLC with electrochemical detection. Test substances were applied via the arterial perfusion medium. Oxotremorine inhibited concentration-dependently the release of 5-HT and 5-HIAA (by 47% at 1 mumol/l). Scopolamine (0.1 mumol/l) did not affect the release of 5-HT and 5-HIAA, but antagonized the effect of oxotremorine. In the presence of TTX (1 mumol/l), oxotremorine (1 mumol/l) increased the release of 5-HT by 150% and that of 5-HIAA by 220%. This increase was completely blocked by scopolamine. Hexamethonium (100 mumol/l) and TTX…
Effect of vasoactive intestinal polypeptide on the release of serotonin from the in vitro vascularly perfused small intestine of guinea pig.
1989
Isolated segments of the guinea pig small intestine were vascularly perfused and the release of endogenous serotonin (5-HT) and its metabolite 5-hydroxyindoleacetic acid (5-HIAA) into the portal vein was measured. All test substances were intraarterially perfused. Vasoactive intestinal polypeptide (VIP, 1 pmol/l-100 nmol/l) inhibited the spontaneous release of 5-HT and 5-HIAA. The maximal inhibitory effect (about 60%) was seen at 100 pmol/l. The effect of VIP on the spontaneous release of 5-HT and 5-HIAA was not changed in the presence of 1 mumol/l tetrodotoxin (TTX). Raising intraluminal pressure by 500 Pa for 5 min increased the release of 5-HT and 5-HIAA by about 25%. Raising the intralu…
Concomitant Small Cell Neuroendocrine Carcinoma of Gallbladder and Breast Cancer
2014
The neuroendocrine carcinoma is defined as a high-grade malignant neuroendocrine neoplasm arising from enterochromaffin cells, usually disposed in the mucosa of gastric and respiratory tracts. The localization in the gallbladder is rare. Knowledge of these gallbladder tumors is limited and based on isolated case reports. We describe a case of an incidental finding of small cell neuroendocrine carcinoma of the gallbladder, observed after cholecystectomy for cholelithiasis, in a 55-year-old female, who already underwent quadrantectomy and sentinel lymph-node biopsy for breast cancer. The patient underwent radiotherapy for breast cancer and six cycles of chemotherapy with cisplatin and etoposi…
Rotavirus stimulates release of serotonin (5-HT) from human enterochromaffin cells and activates brain structures involved in nausea and vomiting
2011
Rotavirus (RV) is the major cause of severe gastroenteritis in young children. A virus-encoded enterotoxin, NSP4 is proposed to play a major role in causing RV diarrhoea but how RV can induce emesis, a hallmark of the illness, remains unresolved. In this study we have addressed the hypothesis that RV-induced secretion of serotonin (5-hydroxytryptamine, 5-HT) by enterochromaffin (EC) cells plays a key role in the emetic reflex during RV infection resulting in activation of vagal afferent nerves connected to nucleus of the solitary tract (NTS) and area postrema in the brain stem, structures associated with nausea and vomiting. Our experiments revealed that RV can infect and replicate in human…
Regulation of serotonin release from the intestinal mucosa.
1991
Summary In the mammalian intestine serotonin (5-hydroxytryptamine, 5-HT) is present in high concentrations in the enterochromaffin cells. The release of 5-HT from the intestinal mucosa is regulated by a complex pattern of neuronal and humoral inputs to the enterochromaffin cells. The enterochromaffin cells appear to be endowed with different inhibitory ( α 2 -adrenoceptors, GABA A - and GABA B -receptors, histamine H 3 -receptors, receptors for vasoactive intestinal polypeptide and somatostatin) as well as stimulatory receptors ( β -adrenoceptors, muscarine and nicotine receptors). The physiological significance of this complex system of receptors is suggested by experiments which demonstra…
Short- and long-term effects of vinblastine on the rat adrenal medulla
1979
The effects of a single high dose (10mg/kg) of vinblastine (vb) sulfate (“Velbe”, Lilly) on the ultrastructure, catecholamine (CA) content and activity of CA-synthesizing enzymes of the rat adrenal medulla were studied for up to 120h after intravenous injection of the drug.
OP0309 Intestinal sclerostin/serotonin axis is modulated by dysbiosis and regulates ilc3 expansion in as patients
2017
Background Sclerostin is an osteocyte-specific factor that binds to low-density lipoprotein receptor-related protein 5 (LRP5) inhibiting the Wnt signaling pathway and possibly contributing to the pathogenesis of Ankylosing spondylitis (AS). Subclinical gut inflammation observed in AS patients is characterized by the presence of dysbiosis and innate immune alterations. In the gut, LRP5 activation by unknown ligands inhibits serotonin production. Serotonin, by inducing glial derived neurotrophic factor (GDNF), controls ILC3 expansion, in the context of glial–ILC3–epithelial cell unit (GIECU). Sclerostin/serotonin axis has been never studied in AS. Objectives Aim of this study was to evaluate …
Control of Gastric Acid Secretion in Somatostatin Receptor 2 Deficient Mice: Shift from Endocrine/Paracrine to Neurocrine Pathways
2007
The gastrin-enterochromaffin-like (ECL) cell-parietal cell axis is known to play an important role in the regulation of gastric acid secretion. Somatostatin, acting on somatostatin receptor type 2 (SSTR2), interferes with this axis by suppressing the activity of the gastrin cells, ECL cells, and parietal cells. Surprisingly, however, freely fed SSTR2 knockout mice seem to display normal circulating gastrin concentration and unchanged acid output. In the present study, we compared the control of acid secretion in these mutant mice with that in wild-type mice. In SSTR2 knockout mice, the number of gastrin cells was unchanged; whereas the numbers of somatostatin cells were reduced in the antru…