Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P43026 (lipopolysaccharide)
 62,215 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

This study was done to examine the role of the vagus nerve in a model of gastric injury during endotoxemia. In conscious rats, lipopolysaccharide (LPS; 20 mg/kg i.p.) treatment for 5 hr prevented macroscopic gastric injury caused by acidified ethanol (150 mM HCl/50% ethanol). In addition, LPS enhanced gastric luminal fluid accumulation, decreased gastric mucosal blood flow (laser Doppler), and increased plasma gastrin levels (radioimmunoassay). Subdiaphragmatic truncal vagotomy, performed 7 days prior to LPS inhibited LPS-induced fluid accumulation, further reduced gastric mucosal blood flow following LPS, and augmented LPS-induced gastrin release compared to those in pyloroplasty controls. Atropine (1 mg/kg i.p.) prevented LPS-induced fluid accumulation but did not influence the effects of LPS on blood flow or gastrin release. Neither vagotomy nor atropine negated LPS-induced gastroprotection. This is the first report to examine the role of cholinergic nerves in the stomach during endotoxemia. The data indicate that LPS causes accumulation of gastric luminal fluid in part through its effects on cholinergic nerves. In contrast, the effects of vagotomy on blood flow and gastrin release following LPS involve a noncholinergic pathway. However, LPS-induced gastroprotection is independent of the vagus nerve.
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PMID:Lipopolysaccharide-induced gastroprotection is independent of the vagus nerve. 1147 6

Intestinal epithelial cells sense short-chain fatty acids (SCFAs) to secrete non-neuronal acetylcholine (ACh). However, the roles of luminalSCFAs and epithelialACh under normal and pathological conditions remain unknown. We examined ileal contractile responses toSCFAs at different ages and their mucosal cholinergic alterations under inflammatory conditions. Ileal contractile responses toSCFAs in 1-day-old pups to 7-week-old mice were compared using an isotonic transducer, and responses to an intraperitoneal injection of lipopolysaccharide (LPS) were analyzed in 7-week-old mice. ThemRNAexpression levels of aSCFAactivate free fatty acid receptor, acetylcholinesterase (AChE), choline acetyltransferase (Chat), and choline transporter-like protein 4 (CTL4) were measured using real-time quantitativeRT-PCRAChE was analyzed by histochemical and optical enzymatic assays. Atropine-sensitive ileal contractile responses toSCFAs occurred in all 1-day-old pups, but were frequently desensitized after the weaning period. These contractile responses were not inhibited by tetrodotoxin and did not appear when the mucosal layer had been scraped off. Contractile desensitization in 7-week-old mice was abolished in the presence of theAChE inhibitor, eserine, which was consistent with increasedAChE activity after weaning. Ileal contractions toSCFAs in adult mice were restored byLPS, which significantly increased the epithelialmRNAexpression of Chat andCTL4. Atropine-sensitive ileal contractile responses toSCFAs constitutively occur in the newborn period, and are desensitized during developmental stages following the up-regulated expression ofAChE in the villous mucosa, but are restored under inflammatory conditions possibly via the release of epithelialACh.
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PMID:Non-neuronal, but atropine-sensitive ileal contractile responses to short-chain fatty acids: age-dependent desensitization and restoration under inflammatory conditions in mice. 2705 93

Orexins are neuropeptides that are implicated in a number of functions. With regard to the gastrointestinal functions, orexin acts centrally to regulate gastric secretion, gastrointestinal motility and visceral sensation. Little is however known about a role of central orexin in the control of intestinal barrier function. The present study was performed to clarify whether brain orexin plays a role in the control of intestinal permeability. Colonic permeability was estimated in vivo by quantifying the absorbed Evans blue in colonic tissue in rats. Intracisternally administered orexin-A but not orexin-B dose-dependently blocked the increased intestinal permeability by lipopolysaccharide (LPS) or corticotropin-releasing factor while intraperitoneally injected orexin-A failed to block it. Atropine or vagotomy abolished the action by central orexin-A. Intravenous injection of 2-deoxy-D-glucose (2-DG), a central vagal stimulant, significantly blocked the LPS-induced increase in intestinal permeability and atropine prevented the action of 2-DG. Intracisternal injection of SB-334687, a selective orexin 1 receptor antagonist, significantly blocked the action of 2-DG-induced improvement of intestinal hyperpermeability. These results suggest that exogenously administered or endogenously released orexin acts centrally to improve the intestinal hyperpermeability by LPS via the vagal cholinergic pathway. The findings also suggest for the first time that the brain could control intestinal permeability. The neuronal rapid protective advantage to the host by improving the intestinal barrier function by the neuropeptide may help us understand the brain-gut interaction in stress sensitive gastrointestinal disorders like irritable bowel syndrome associated with the altered intestinal permeability.
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PMID:Brain orexin improves intestinal barrier function via the vagal cholinergic pathway. 3167 32