[Show abstract][Hide abstract] ABSTRACT: To determine if the observed paracellular sucrose leak in Barrett's esophagus patients is due to their proton pump inhibitor (PPI) use.
The in vivo sucrose permeability test was administered to healthy controls, to Barrett's patients and to non-Barrett's patients on continuous PPI therapy. Degree of leak was tested for correlation with presence of Barrett's, use of PPIs, and length of Barrett's segment and duration of PPI use.
Barrett's patients manifested a near 3-fold greater, upper gastrointestinal sucrose leak than healthy controls. A decrease of sucrose leak was observed in Barrett's patients who ceased PPI use for 7 d. Although initial introduction of PPI use (in a PPI-naïve population) results in dramatic increase in sucrose leak, long-term, continuous PPI use manifested a slow spontaneous decline in leak. The sucrose leak observed in Barrett's patients showed no correlation to the amount of Barrett's tissue present in the esophagus.
Although future research is needed to determine the degree of paracellular leak in actual Barrett's mucosa, the relatively high degree of leak observed with in vivo sucrose permeability measurement of Barrett's patients reflects their PPI use and not their Barrett's tissue per se.
Full-text · Article · Jun 2012 · World Journal of Gastroenterology
[Show abstract][Hide abstract] ABSTRACT: Inflammatory bowel disease (IBD), including Crohn's Disease (CD) and Ulcerative Colitis (UC), is characterized by inflammation of the gastrointestinal tract. In UC, inflammation is confined to the mucosa, initially involving the rectum, and may extend proximally to involve the entire colon. In CD, transmural inflammation may affect any portion of the GI tract. The etiology of these disease processes has remained unclear. Therapies are aimed at reducing inflammation and thereby improving symptomatology and morbidity. Traditional medical therapies have included corticosteroids, aminosalicylates, and immunomodulators. Within the past decade, another class of medications has been utilized targeting Tumor Necrosis Factor (TNF), a key, early signaling molecule in the inflammatory cascade. Increased levels of TNF have been found in the blood, epithelial tissue, and stool of patients with active IBD. Anti-TNF medications can not only have direct effects on immune system components, but they also can ameliorate apoptotic cell death and tight junction compromise in the gastrointestinal epithelium. Several randomized, placebo controlled studies have demonstrated the efficacy of these medications in achieving induction and maintaining remission of disease. Their safety profile, however, remains a concern. There has been a reported association of biologic therapy and increased opportunistic infections. A link between biologic therapy and the development of certain malignancies has also been described. Despite these associations, TNF blockade remains an important therapeutic development in the modern therapy of IBD. The role of barrier breakdown at the tight junction level in IBD, and of TNF induction of barrier disruption, is also discussed.
Full-text · Article · Nov 2010 · Current Molecular Pharmacology
[Show abstract][Hide abstract] ABSTRACT: Proton pump inhibitors are the second most commonly prescribed drug class in the United States. The increased utilization of PPIs parallels the rising incidence of reflux disease. Owing to their clinical efficacy and relative lack of tachyphylaxis, PPIs have largely displaced H-2 receptor antagonists in the treatment of acid peptic disorders. The elevation of intragastric pH and subsequent alterations of gastric physiology induced by PPIs may yield undesired effects within the upper GI tract. The ubiquity of the various types of H(+), K(+)-ATPase could also contribute to non-gastric effects. PPIs may influence physiology in other ways, such as inducing transepithelial leak.
Full-text · Article · May 2009 · Drug discovery today