Lionel Buéno

Learn More
BACKGROUND AND AIMS Intestinal barrier impairment is incriminated in the pathophysiology of intestinal gut disorders associated with psychiatric comorbidity. Increased intestinal permeability associated with upload of lipopolysaccharides (LPS) translocation induces depressive symptoms. Gut microbiota and probiotics alter behavior and brain neurochemistry.(More)
OBJECTIVES Diarrhoea-predominant irritable bowel syndrome (IBS-D) is characterised by elevated colonic lumenal serine protease activity. The aims of this study were (1) to investigate the origin of this elevated serine protease activity, (2) to evaluate if it may be sufficient to trigger alterations in colonic paracellular permeability (CPP) and(More)
BACKGROUND & AIMS Stressful life events are supposed to be involved in various diseases such as inflammatory bowel diseases and irritable bowel syndrome. Impairment of the intestinal epithelial barrier function is a suspected consequence of stress, but the underlying mechanisms remain unclear. This study aimed to determine the mechanisms through which(More)
BACKGROUND Stressful events in the early period of life (for example, maternal deprivation) have been shown to modify adult immune and gastrointestinal tract functions. The present study aimed to establish whether maternal deprivation affects colonic epithelial barrier and the development of an experimental colitis in adult rats. METHODS Male Wistar rat(More)
Irritable bowel syndrome (IBS) is one of the most common gastrointestinal disorders, characterized by abdominal pain and disturbed defecation that cannot be explained by structural abnormalities. Although IBS symptoms (visceral pain, increased gut permeability, motility alterations) are clearly established, the etiology of this pathology is loosely(More)
Proteinase-activated receptor (PAR)-2, a G-protein-coupled receptor for trypsin and mast cell tryptase, is highly expressed in the intestine. Luminal trypsin and tryptase are elevated in the colon of inflammatory bowel disease patients. We hypothesized that luminal proteinases activate PAR-2 and induce colonic inflammation. Mice received intracolonically(More)
Neonatal maternal deprivation (NMD) increases gut paracellular permeability (GPP) through mast cells and nerve growth factor (NGF), and modifies corticotrophin-releasing factor (CRF) and corticosterone levels. CRF, corticosterone and mast cells are involved in stress-induced mucosal barrier impairment. Consequently, this study aimed to specify whether(More)
BACKGROUND & AIMS Maternal deprivation (MD) increases nerve growth factor (NGF) expression and colonic mast cell density and alters visceral sensitivity. This study aimed to establish whether NGF overexpression induced by neonatal stress is involved in altered visceral sensitivity and gut mucosal integrity in adult rats. METHODS Male Wistar rat pups were(More)
BACKGROUND Neonatal maternal deprivation induces colonic alterations in adult rats, such as hypersensitivity to distension or an increase in paracellular permeability, characteristics of irritable bowel syndrome (IBS) patients. Recent studies described neuroimmune alterations in the colonic mucosa of IBS patients. METHODS Male Wistar rats were submitted(More)
The effect of a mental stress model corresponding to conditioned fear on cecocolonic motility was evaluated electromyographically in intact and hypophysectomized rats equipped with electrodes implanted in the cecum and proximal colon over a long period and a small polyethylene catheter inserted into the right lateral ventricle of the brain. Intact fasted(More)