Enteroendocrine cells and 5-HT availability are altered in mucosa of guinea pigs with TNBS ileitis

Abstract

Enteroendocrine cells act as sensory transducers, releasing 5-HT and numerous peptides that are involved in regulating motility, secretion, and gut sensation. The action of mucosal 5-HT is terminated by a 5-HT reuptake transporter (SERT). In this study, we examined the hypothesis that ileitis leads to changes in enteroendocrine cell populations and mucosal 5-HT availability. Ileitis was induced in guinea pigs by intraluminal injection of 2,4,6-trinitrobenzenesulfonic acid and experiments were conducted 3, 7, and 14 days after treatment. The number of somatostatin, neurotensin, and 5-HT-immunoreactive cells increased at 3 and 7 days of ileitis, respectively, whereas no significant changes in the numbers of cholecystokinin, glucagon-like peptide-2, glucose-dependent insulinotropic peptide, and peptide YY-immunoreactive cells were observed. Chemical stimulation of the inflamed mucosa with sodium deoxycholic acid significantly increased 5-HT release compared with basal release. Mechanical stimulation of the mucosa potentiated the effect of the chemical stimuli at day 7. Epithelial SERT immunoreactivity was significantly reduced during the time course of inflammation. Thus changes in enteroendocrine cell populations and 5-HT availability could contribute to the altered motility and secretion associated with intestinal inflammation by disrupting mucosal signaling to enteric nerves involved in peristaltic and secretory reflexes.

Regulation of serotonin transporter activity by adenosine in intestinal epithelial cells

“…Recent reports have confirmed the relevance of the SERT function for the control of intestinal activity [30,31]. SERT expression and activity are affected in intestinal inflammation [10,[14][15][16] and inflammatory mediators have been shown to inhibit SERT function and expression in epithelial cells [12,13].…”

“…Numerous studies have concluded that the alteration of the GI serotoninergic system may be involved in the origin and/or prevalence of chronic GI pathologies such as Irritable Bowel Syndrome (IBS) and Inflammatory Bowel Disease (IBD) [10,11]. Recent results have demonstrated that SERT expression is downregulated and SERT activity is impaired in intestinal epithelial cells treated with pro-inflammatory factors [12,13], in animal models and human forms of intestinal inflammation [10,[14][15][16].…”

“…Recent results have demonstrated that SERT expression is downregulated and SERT activity is impaired in intestinal epithelial cells treated with pro-inflammatory factors [12,13], in animal models and human forms of intestinal inflammation [10,[14][15][16].…”

Avaliação dos efeitos de 5-hidroxitriptofano em-hidroxibenzilhidrazine associados a Lactobacillus spp. na morfometria intestinal e imunomarcação de serotonina em frangos de corte desafiados com Salmonella Enteridis

“…Os resultados observados por O` Hara et al (2004) indicam que a recaptação de serotonina é realmente reduzida durante a inflamação por Citrobacter rodentium, onde as células imunomarcadas para SERT foram reduzidas 10 dias após a infecção. Mesmos resultados foram observados em colites ulcerativas em humanos (Coates et al 2004).…”

Muscularis mucosae - the forgotten sibling

“…The mucosal mast cells may therefore function as an expulsion system of intestinal nematode infections. In recent, O'Hara et al (2004) presented evidence that enteroendocrine cells and serotonin availability in intestinal mucosa were altered in experimental ileitis. This indicates that pathological changes in the transduction pathway between mucosal endocrine cells and primary afferent nerve terminals may lead to decreased motility and secretion in irritable bowel diseases.…”