Protective role of the epithelium of the small intestine and colon.

摘要: : The intestinal epithelium must selectively absorb nutrients but exclude luminal pathogens and pro-inflammatory molecules from host tissues. It is topographically organised with proliferating cells buried deep in the crypts functionally mature lining surface or villus. This ensures efficient barrier function at interface relative protection of stem insults. rapid turnover necessitates high energy requirements. Luminal glutamine butyrate are necessary to maintain optimal status small large epithelium, respectively. passage macromolecules across impeded by enterocytes intercellular tight junctions. Multiple factors have been recognised that alter paracellular permeability, relatively little known regarding control transcellular macromolecules. is, however, more than just a physical barrier. can detoxify xenobiotics. secretes "protective" including immunoglobulins, mucus, trefoil peptides, defensins into lumen, while epithelial release chemokines, cytokines, other inflammatory mediators may initiate mucosal immunity inflammation. response injurious stimuli complex lead events that, for example, enhance function, reduce their susceptibility injury, recruit secondary protective mechanisms. rapidly migrates breeches its continuity, process severe sets up microenvironment amenable regeneration. Repair also regulated multiple levels. Thus, complexity active passive roles protecting organism environment now unfolding. knowledge gained offers insight pathogenesis diseases such as bowel disease form rational basis future design novel therapeutic strategies management.