Objectives: Serotonin (5-hydroxytryptamine, 5-HT) metabolism may be altered in gut disorders, including in the irritable bowel syndrome (IBS). We assessed in patients with IBS vs. healthy controls (HCs) the number of colonic 5-HT-positive cells; the amount of mucosal 5-HT release; their correlation with mast cell counts and mediator release, as well as IBS symptoms; and the effects of mucosal 5-HT on electrophysiological responses in vitro.
Methods: We enrolled 25 Rome II IBS patients and 12 HCs. IBS symptom severity and frequency were graded 0-4. 5-HT-positive enterochromaffin cells and tryptase-positive mast cells were assessed with quantitative immunohistochemistry on colonic biopsies. Mucosal 5-HT and mast cell mediators were assessed by high-performance liquid chromatography or immunoenzymatic assay, respectively. The impact of mucosal 5-HT on electrophysiological activity of rat mesenteric afferent nerves was evaluated in vitro.
Results: Compared with HCs, patients with IBS showed a significant increase in 5-HT-positive cell counts (0.37 ± 0.16% vs. 0.56 ± 0.26%; P=0.039), which was significantly greater in patients with diarrhea-predominant IBS vs. constipation-predominant IBS (P=0.035). Compared with HCs, 5-HT release in patients with IBS was 10-fold significantly increased (P < 0.001), irrespective of bowel habit, and was correlated with mast cell counts. A significant correlation was found between the mucosal 5-HT release and the severity of abdominal pain (r(s)=0.582, P=0.047). The area under the curve, but not peak sensory afferent discharge evoked by IBS samples in rat jejunum, was significantly inhibited by the 5-HT₃ receptor antagonist granisetron (P<0.005).
Conclusions: In patients with IBS, 5-HT spontaneous release was significantly increased irrespective of bowel habit and correlated with mast cell counts and the severity of abdominal pain. Our results suggest that increased 5-HT release contributes to development of abdominal pain in IBS, probably through mucosal immune activation.
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http://dx.doi.org/10.1038/ajg.2011.86 | DOI Listing |
Biomedicines
November 2024
Department of Nephrology, The First Affiliated Hospital of Xi'an Medical University, Xi'an 710077, China.
Objects: Taurine exhibits protective effects in the context of cardiovascular pathophysiology. A range of evidence suggests that hypertension activates inflammatory responses and oxidative stress in the paraventricular nucleus (PVN), elevating the arterial tone and sympathetic activity, while it induces gut-brain axis dysfunction in the context of hypertension. However, the mechanism underlying taurine's anti-hypertensive effects via the gut-brain axis remains unclear.
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January 2025
Institute of Human Behavior & Genetics, Korea University, Seoul 02841, Republic of Korea.
This study investigated the effects of on alleviating loperamide-induced constipation. To evaluate the efficacy of in Sprague-Dawley (SD) rats, fecal parameters, the intestinal transit rate, and changes in intestinal mucosal cells were measured through histological analysis. Additionally, serotonin levels, water absorption, tight junction-related gene expression, and the cecal short-chain fatty acid (SCFA) content were analyzed.
View Article and Find Full Text PDFGut Microbes
November 2024
Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Capital Medical University, Beijing, China.
The consumption of high-fat diets (HFD) and an imbalance in gut microbiome are linked to obesity. However, the intricate connection between them and the underlying mechanisms involved in lipid digestion and absorption remain largely unclear. This study shows that after 12 weeks of HFD feeding, mice exhibit two distinct metabolic phenotypes with significant differences in gut microbiota composition.
View Article and Find Full Text PDFComp Biochem Physiol C Toxicol Pharmacol
January 2025
The Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao 266003, PR China.
Ammonia nitrogen, a common aquaculture pollutant, harms crustaceans by causing intestinal inflammation, though its exact mechanisms are unclear. Thus, we exposed shrimp to 0, 2, 10 and 20 mg/L NHCl exposure for 0, 3, 6, 12, 24, 48, 72 h, and explored the intestinal stress, apoptosis, proliferation, inflammation and its histopathological changes. This research indicated that ammonia nitrogen exposure heightens plasma dopamine (DA), 5-hydroxytryptamine (5-HT), norepinephrine (NE), and acetylcholine (ACh) levels, alters gene expression of neurotransmitter receptors in the intestine, triggering the PLCCa pathway and induces endoplasmic reticulum stress.
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October 2024
CQ-VR, Chemistry Research Center, Department of Agronomy, School of Agrarian and Veterinary Sciences, University of Trás-os-Montes and Alto Douro, 5000-801 Vila Real, Portugal.
Wine vinegar, valued for its ancient origins and culinary versatility, has garnered scientific interest due to its complex composition and potential health benefits. This study aims to explore the nutritional and bioactive properties of different wine vinegars, focusing on their amino acid content, particularly tryptophan-derived molecules such as serotonin and melatonin. White wine vinegar, red wine vinegar, port wine vinegar, and balsamic vinegar from the Douro and Rioja regions were analyzed using high-performance liquid chromatography and solid-phase extraction (HPLC-SPE).
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