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Biochemical Pharmacology Jan 1994The effect of Ruthenium red (RR) on ionic currents and catecholamine secretion was studied in chromaffin cells. This polycation inhibited 59 mM potassium-stimulated...
The effect of Ruthenium red (RR) on ionic currents and catecholamine secretion was studied in chromaffin cells. This polycation inhibited 59 mM potassium-stimulated 45Ca2+ uptake in a concentration-dependent manner (IC50 = 5 +/- 0.2 microM). This effect was more evident at extracellular calcium concentrations over 1 mM and was not abolished by neuraminidase pretreatment. RR also inhibited potassium-stimulated catecholamine secretion (IC50 = 6 +/- 0.9 microM). These results were corroborated by patch-clamp in whole-cell recordings. RR inhibited chromaffin cell calcium currents (IC50 = 7 microM) without affecting significantly either sodium or potassium currents. Radioligand binding studies in adrenomedullary plasma membranes showed that RR inhibited [125I]omega-conotoxin GVIA binding but it had no effect on specific binding of [3H]nitrendipine. The effect of the RR on calcium currents was additive with the inhibitory effect observed with 10 microM nitrendipine. The residual dihydropyridine-resistant calcium current was inhibited with a potency similar to that determined under control conditions in the absence of nitrendipine. These results demonstrate that RR selectively inhibits calcium channels; however, this polycation was not selective for a particular calcium channel subtype.
Topics: Animals; Calcium Channel Blockers; Cattle; Cell Membrane; Dihydropyridines; Enterochromaffin Cells; Iodine Radioisotopes; Nitrendipine; Norepinephrine; Peptides; Ruthenium Red; Tritium; omega-Conotoxin GVIA
PubMed: 7508229
DOI: 10.1016/0006-2952(94)90010-8 -
The Anatomical Record Mar 1948
Topics: Animals; Enterochromaffin Cells; Gastric Mucosa; Helicobacter Infections; Rats
PubMed: 18906251
DOI: 10.1002/ar.1091000304 -
Journal of Cardiovascular Pharmacology 1985The enterochromaffin (EC) cell system is distributed throughout the entire gastrointestinal tract. Enterochromaffin cells are the major source of intestinal serotonin...
The enterochromaffin (EC) cell system is distributed throughout the entire gastrointestinal tract. Enterochromaffin cells are the major source of intestinal serotonin (5-HT), but separate subpopulations of EC cells may synthesize and store peptides as substance P (SP), motilin, and enkephalin as well. Of special interest is that 5-HT and SP, which may coexist in EC cells, have several functional similarities, i.e., inhibition of gastric acid secretion, stimulation of intestinal motility, and secretion of water and electrolytes. Carcinoid tumors are derived from the gut endocrine system. Depending on site of origin, carcinoids are divided into foregut, midgut, and hindgut derivatives with different clinical symptoms. A common biochemical feature of midgut carcinoids is the production of 5-HT and SP. Histochemically, midgut carcinoids are characterized by the argentaffin reaction--a direct reduction of silver salts owing to 5-HT. Specific antisera for the immunocytochemical demonstration of secretory products are available as well. Despite their relative infrequency, carcinoids are the most common small intestinal tumors. The common appendix tumors generally have a benign clinical course, whereas the small intestinal tumors have different growth patterns and frequently metastasize with increasing size, and may thus give rise to the carcinoid syndrome (diarrhea, facial flush, right-sided cardiac valvular disease, and asthma). Carcinoid symptoms first appear when hepatic inactivation of 5-HT is exceeded, unless the carcinoid has an extraintestinal localization, for example, ovarian lesions may elicit symptoms in the absence of hepatic disease owing to direct secretion into systemic circulation.(ABSTRACT TRUNCATED AT 250 WORDS)
Topics: APUD Cells; Animals; Carcinoid Tumor; Chromaffin System; Enterochromaffin Cells; Gastrointestinal Neoplasms; Humans; Malignant Carcinoid Syndrome; Neoplasm Transplantation; Rats; Serotonin
PubMed: 2412066
DOI: 10.1097/00005344-198500077-00023 -
Journal of Neuroimmunology Jan 2004The involvement of serotonin (5-hydroxytryptamine; 5-HT) in immunoregulation has been well documented. Gut mucosa is a large reservoir of 5-HT most of which is...
Proximity between 5-HT secreting enteroendocrine cells and lymphocytes in the gut mucosa of rhesus macaques (Macaca mulatta) is suggestive of a role for enterochromaffin cell 5-HT in mucosal immunity.
The involvement of serotonin (5-hydroxytryptamine; 5-HT) in immunoregulation has been well documented. Gut mucosa is a large reservoir of 5-HT most of which is attributed to gut endocrine cells. In this study, we examined the anatomical relationship among 5-HT immunoreactive cells and T and B lymphocytes in the gut mucosa of rhesus monkeys (Macaca mulatta). 5-HT, CD3 and CD20 immunoreactive cells were immunofluorescently labeled and visualized by confocal microscopy. 5-HT immunoreactive cells were primarily found within the epithelium of the intestine and were present at all levels of the gastrointestinal tract. Many 5-HT immunoreactive cells were in contact with, or very close proximity to CD3(+) and CD20(+) lymphocytes. These results provide morphological evidence to suggest interactions between 5-HT secreting enteroendocrine cells and lymphocytes in the gut mucosa. This further supports a possible role of 5-HT in mucosal immune responses.
Topics: Animals; Enterochromaffin Cells; Enteroendocrine Cells; Gastric Mucosa; Immunity, Mucosal; Intestinal Mucosa; Lymphocytes; Macaca mulatta; Serotonin
PubMed: 14698846
DOI: 10.1016/j.jneuroim.2003.10.044 -
BMC Microbiology Nov 2021Accumulating evidence supports the pivotal role of intestinal flora in irritable bowel syndrome (IBS). Serotonin synthesis by enterochromaffin (EC) cells is influenced...
BACKGROUND
Accumulating evidence supports the pivotal role of intestinal flora in irritable bowel syndrome (IBS). Serotonin synthesis by enterochromaffin (EC) cells is influenced by the gut microbiota and has been reported to have an interaction with IBS. The comparison between the microbiota of the caecal and colonic mucosa in IBS has rarely been studied. The aim of this study was to investigate the relationship between the gut microbiota, EC cells in caecum and descending colon, and diarrhoea-predominant IBS (IBS-D) symptoms.
RESULTS
A total of 22 IBS-D patients and 22 healthy controls (HCs) were enrolled in our study. Hamilton anxiety (HAM-A) and Hamilton depression (HAM-D) grades increased significantly in IBS-D patients. In addition, the frequency of defecation in IBS-D patients was higher than that in HCs. Among the preponderant bacterial genera, the relative abundance of the Ruminococcus_torques_ group increased in IBS-D patients in caecum samples while Raoultella and Fusobacterium were less abundant. In the descending colon, the abundance of the Ruminococcus_torques_group and Dorea increased in IBS-D patients and Fusobacterium decreased. No difference was observed between the descending colon and caecum in regards to the mucosal-associated microbiota. The number of EC cells in the caecum of IBS-D patients was higher than in HCs and the expression of TPH1 was higher in IBS-D patients both in the caecum and in the descending colon both at the mRNA and protein level. Correlation analysis showed that the Ruminococcus_torques_group was positively associated with HAM-A, HAM-D, EC cell number, IBS-SSS, degree of abdominal pain, frequency of abdominal pain and frequency of defecation. The abundance of Dorea was positively associated with EC cell number, IBS-SSS, HAM-A, HAM-D and frequency of abdominal pain.
CONCLUSIONS
EC cell numbers increased in IBS-D patients and the expression of TPH1 was higher than in HCs. The Ruminococcus torques group and Dorea furthermore seem like promising targets for future research into the treatment of IBS-D patients.
Topics: Adult; Bacteria; Case-Control Studies; Cecum; Colon; Diarrhea; Enterochromaffin Cells; Feces; Female; Gastrointestinal Microbiome; Humans; Intestinal Mucosa; Irritable Bowel Syndrome; Male; Middle Aged; Serotonin
PubMed: 34773967
DOI: 10.1186/s12866-021-02380-2 -
Scandinavian Journal of Gastroenterology 1992Both oxyntic mucosal progenitor cells and enterochromaffin-like (ECL) cells are under the trophic control of gastrin. We studied the effect of discontinuing...
Both oxyntic mucosal progenitor cells and enterochromaffin-like (ECL) cells are under the trophic control of gastrin. We studied the effect of discontinuing omeprazole-induced hypergastrinemia on cell proliferation and ECL cell function in the rat oxyntic mucosa. All rats had hypergastrinemia after 16 days' omeprazole administration, and the proliferation rate of both progenitor and ECL cells was increased, whereas it was decreased 5 days after withdrawal of omeprazole. Circulating gastrin had normalized by then. The proliferative activity of the progenitor cells returned to normal within 10 days, whereas that of the ECL cells remained suppressed for at least 20 days. The histidine decarboxylase activity of the ECL cells changed in parallel with their proliferative activity. These data suggest either a down-regulation of membrane receptors or the involvement of still unknown inhibitors of mitotic activity and ECL cell function in the oxyntic mucosa.
Topics: Animals; Enterochromaffin Cells; Gastric Mucosa; Gastrins; Histamine; Histidine Decarboxylase; Male; Omeprazole; Parietal Cells, Gastric; Radionuclide Imaging; Rats; Rats, Inbred Strains; Stem Cells; Thymidine
PubMed: 1561530
DOI: 10.3109/00365529209165437 -
Nature May 1975
Topics: Animals; Anura; Appendix; Chromaffin System; Chromatography, Thin Layer; Enterochromaffin Cells; Humans; Intestinal Mucosa; Melanophores; Melatonin; Skin; Tissue Extracts
PubMed: 1128697
DOI: 10.1038/255344a0 -
American Journal of Physiology.... May 2022Cross talk between the gastrointestinal tract and brain is of significant relevance for human health and disease. However, our understanding of how the gut and brain...
Cross talk between the gastrointestinal tract and brain is of significant relevance for human health and disease. However, our understanding of how the gut and brain communicate has been limited by a lack of techniques to identify the precise spatial relationship between extrinsic nerve endings and their proximity to specific cell types that line the inner surface of the gastrointestinal tract. We used an in vivo anterograde tracing technique, previously developed in our laboratory, to selectively label single spinal afferent axons and their nerve endings in mouse colonic mucosa. The closest three-dimensional distances between spinal afferent nerve endings and axonal varicosities to enterochromaffin (EC) cells, which contain serotonin (5-hydroxytryptamine; 5-HT), were then measured. The mean distances (± standard deviation) between any varicosity along a spinal afferent axon or its nerve ending, and the nearest EC cell, were 5.7 ± 6.0 μm (median: 3.6 μm) and 26.9 ± 18.6 μm (median: 24.1 μm), respectively. Randomization of the spatial location of EC cells revealed similar results to this actual data. These distances are ∼200-1,000 times greater than those between pre- and postsynaptic membranes (15-25 nm) that underlie synaptic transmission in the vertebrate nervous system. Our findings suggest that colonic 5-HT-containing EC cells release substances to activate centrally projecting spinal afferent nerves likely via diffusion, as such signaling is unlikely to occur with the spatial fidelity of a synapse. We show an absence of close physical contact between spinal afferent nerves and 5-HT-containing EC cells in mouse colonic mucosa. Similar relative distances were observed between randomized EC cells and spinal afferents compared with actual data. This spatial relationship suggests that substances released from colonic 5-HT-containing EC cells are unlikely to act via synaptic transmission to neighboring spinal afferents that relay sensory information from the gut lumen to the brain.
Topics: Animals; Brain-Gut Axis; Colon; Enterochromaffin Cells; Mice; Serotonin
PubMed: 35293258
DOI: 10.1152/ajpgi.00019.2022 -
The Journal of Pathology and... Oct 1964
Topics: Cell Biology; Chromaffin System; Coloring Agents; Cystadenoma; Cystadenoma, Mucinous; Enterochromaffin Cells; Female; Genitalia; Genitalia, Female; Humans; Ovarian Cysts; Ovarian Neoplasms; Silver Proteins; Staining and Labeling
PubMed: 14226420
DOI: 10.1002/path.1700880211 -
Nature Reviews. Gastroenterology &... Aug 2017
Topics: Enterochromaffin Cells; Neural Pathways; Sensory Receptor Cells
PubMed: 28676710
DOI: 10.1038/nrgastro.2017.91