Ethanol-induced alterations of matrix network in the duodenal mucosa of chronic alcohol abusers

Excessive consumption of alcoholic beverages may be associated with gastroi ntestinal symptoms, including dyspepsia and diarrhoea. It is not clear whet her or not chronic alcohol ingestion damages the mucosa of the small intest ine. We investigated the effect of chronic alcohol abuse on the duodenal mu cosa, and particularly on its extracellular matrix (ECM) network. Duoenal b iopsy specimens were obtained during upper gastrointestinal endoscopy from 50 chronic alcoholics without cirrhosis and 10 healthy subjects. Morphologi cal studies were performed by routine histology, immunohistochemistry and e lectron microscopy. Morphometry of duodenal tissues was performed with a co mputerized image analyser. No significant duodenal epithelial changes were found in alcoholics, despite an evident reduction in the enterocyte turnove r. Myofibroblast-like cells were significantly increased in the villus stro ma of alcoholics in comparison to controls. These cells stained positively for desmin, alpha-smooth muscle actin and for several ECM components. In al cohol abusers the thickness of the mucosal basement membrane was greater an d the staining for collagen I and III was enhanced both in the basement mem brane and in the villus stroma. A higher expression of tenascin was also se en at the base of villi of alcoholics. Chronic alcohol abuse may induce fib rosis of duodenal villi which is associated with a transformation of villus juxta-parenchymal cells into active subepithelial myofibroblast-like cells able to produce different ECM components.