Abstract: The invention provides prophylactic and therapeutic methods for administering a ?-opioid receptor antagonist, e.g., N-methylnaltrexone or a salt thereof, to treat cell barrier diseases and disorders, such as endothelial and epithelial cell barrier diseases and disorders, e.g., sepsis. Methods of reducing at least a symptom of sepsis and the risk of developing sepsis are also provided.

Abstract: The invention provides prophylactic and therapeutic methods for administering a ?-opioid receptor antagonist, e.g., N-methylnaltrexone or a salt thereof, to treat cell barrier diseases and disorders, such as endothelial and epithelial cell barrier diseases and disorders, e.g., inflammatory bowel disease. Methods of reducing the symptoms of inflammatory bowel disease and the risk of developing inflammatory bowel disease are also provided.

Abstract: The invention provides prophylactic and therapeutic methods for administering a ?-opioid receptor antagonist to treat cell barrier diseases and disorders, such as endothelial and epithelial cell barrier diseases and disorders. The diseases or disorders may amenable to the methods include inflammation, such as acute lung injury, atherosclerosis, gut-derived sepsis, a burn injury, neonatal necrotizing enterocolitis, severe neutropenia, toxic colitis, inflammatory bowel disease, enteropathy, transplant rejection, pouchitis, pig belly (pig-bel), Pseudomonas-mediated opthalmologic infection, Pseudomonas-mediated otologic infection and Pseudomonas-mediated cutaneous infection. More generally, epithelial cell barrier disorders are contemplated as amenable to the prophylactic and therapeutic methods. The diseases and disorders may be induced by microbial pathogens, including bacterial pathogens such as Pseudomonas aeruginosa.