Role of 5-hydroxytryptamine in the dumping syndrome after gastrectomy: histochemical study

Mechanical stimulation activates Galphaq signaling pathways and 5-hydroxytryptamine release from human carcinoid BON cells

5-Hydroxytryptamine (5-HT) released from enterochromaffin cells activates secretory and peristaltic reflexes necessary for lubrication and propulsion of intestinal luminal contents. The aim of this study was to identify mechanosensitive intracellular signaling pathways that regulate 5-HT release. Human carcinoid BON cells displayed 5-HT immunoreactivity associated with granules dispersed throughout the cells or at the borders. Mechanical stimulation by rotational shaking released 5-HT from BON cells or from guinea pig jejunum during neural blockade with tetrodotoxin. In streptolysin O-permeabilized cells, guanosine 5'-O- (2-thiodiphosphate) (GDP-beta-S) and a synthetic peptide derived from the COOH terminus of Galphaq abolished mechanically evoked 5-HT release, while the NH(2)-terminal peptide did not. An antisense phosphorothioated oligonucleotide targeted to a unique sequence of Galphaq abolished mechanically evoked 5-HT release and reduced Galphaq protein levels without affecting the expression of Galpha(11). Depletion and chelation of extracellular calcium did not alter mechanically evoked 5-HT release, whereas depletion of intracellular calcium stores by thapsigargin and chelation of intracellular calcium by 1,2-bis (o-Aminophenoxy) ethane-N,N,N',N'-tetraacetic acid tetra (acetoxymethyl) ester (BAPTA-AM) reduced 5-HT release. Mechanically evoked 5-HT release was inhibited by somatostatin-14 in a concentration-dependent manner. The results suggest that mechanical stimulation of enterochromaffin-derived BON cells directly or indirectly stimulates a G protein-coupled receptor that activates Galphaq, mobilizes intracellular calcium, and causes 5-HT release.

The successful application of jejunal interposition for severe dumping syndrome: report of a case

We report herein the case of a 76-year-old man with intractable dumping syndrome which had manifested itself 3 years after he underwent a gastric resection and Billroth I reconstruction for a gastric ulcer. Despite aggressive medical therapy by the time of admission, he had suffered from disabling dumping symptoms for 9 years. In an attempt to relieve these symptoms, a 15-cm segment of the jejunum was placed isoperistaltically between the lesser curvature of the remnant stomach and the duodenum, and a selective vagotomy was performed. The dumping symptoms that he had experienced preoperatively completely disappeared after the revisory surgery. Postoperatively, an upper gastrointestinal series demonstrated a larger gastric pouch and slower gastric passage into the small intestine than what was seen preoperatively, while gastric emptying studies using the acetaminophen method also showed normal patterns in both the early and late postoperative phases. Thus, we consider that this surgical procedure is a simple and effective way to inhibit rapid gastric emptying and to slow intestinal transit in the treatment of dumping syndrome.

Serotonin containing and histamine containing cells in human stomach. Identification of these cells by fluorescent microscope and electron microscope

Paraformaldehyde (PF) treatment of epithelial cells of human stomach revealed intense yellow fluorescent granules within the cells. These granules were identified as serotonin on microspectrofluorometry. Serotonin containing cells were also identified as enterochromaffin cells (EC cells) under electron microscope and by the histochemical analysis. O-phthalaldehyde treatment (OPT) of epithelial cells in human stomach demonstrated whitish blue intracellular granules under fluorescence microscope. The cells containing these granules were identified as histamine containing cells on microspectrofluorometry, because of accordance in excitation and emission spectra with authentic histamine. Histamine-containing cells were considered to be identical to the mast cells, because of metachromatic property on toluidine blue staining and of close structural similarities under electron microscope.

Serotonin, noradrenaline, dopamine metabolites in transcendental meditation-technique

The highly significant increase of 5-HIAA (5-hydroxyindole-3-acetic acid) in Transcendental Meditation technique suggests systemic serotonin as "rest and fulfillment hormone" of deactivation-relaxation. Furthermore 5-HT (5-hydroxytryptamine, serotonin) is considered to be the EC-cell (enterochromaffine-cell) hormone requested by Fujita and Kobayashi and its role for EEG synchronisation via area postrema chemoreceptor as anti arousal agent is being discussed. The significant decrease of the catecholamine metabolite VMA (vanillic-mandelic acid) in meditators, that is associated with a reciprocal increase of 5-HIAA supports as a feedback necessity the "rest and fulfillment response" versus "fight and flight". As the adreno medullary tissue serves for hormonal reinforcement of orthosympathetic activity, the Enterochromaffine Cell System (having taken the form of distinct organs in some species as octopus and discoglossus) is suggested to serve via serotonin for humoral reinforcement of parasympathetic activity in deep relaxation.

On the possible role of intestinal hormones as the diarrhoeagenic messenger in cholera

Cholera enterotoxin introduced into the duodenum of young rabbits causes severe degranulation of the enterochromaffin (EC) cells as revealed by electron microscopy. In the mucosal epithelium fixed mainly 1 hr after toxin administration, many of the basal granules of the EC cells are swollen up and open to the basal and lateral cell surface. The EC cells of the rabbit, as it is the rule for intestinal endocrine cells in mammals, are open to the lumen with an apical process covered by microvilli. A hypothesis is proposed that cholera toxin stimulates this apical receptor of the EC cells and that the aminic (serotonin) and polypeptide (motilin?) products of the cells released by the stimulus may mediate the diarrhoeagenic action of cholera enterotoxin.

The effect of gastrectomy on serotonin metabolism in the human portal vein

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Ulcerogenic effect of 5-hydroxytryptamine (serotonin) in the stomach: histochemical study by fluorescent method

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