New insights into intestinal secretion

Apart from malabsorption and intestinal barrier dysfunction (via a ‘leak-flux’ mechanism), diarrhoea may reflect active ion secretion in the small intestine and/or colon. In recent years, our understanding about intestinal secretory mechanisms has increased enormously. Important new findings are (1) chloride, bicarbonate and potassium may be secreted simultaneously, but via independent transport processes and (2) movement of a specific ion across cell membranes may occur via several types of channels selective for that ion, but differing in their molecular structure and intrinsic biophysical properties. Additionally, Linley and coworkers now present evidence that (3) specific types of chloride and potassium channels involved in chloride and potassium secretion are differentially expressed in the apical membrane of enterocytes and goblet cells along the surface cell-crypt cell axis. Thus, we are now in a position to reconsider the ancient concept of exclusively secretory crypt cells and absorptive surface cells.1 In general,...

Source: Gut - August 3, 2014 Category: Gastroenterology Authors: Schulzke, J. D., Siegmund, B., Gunzel, D. Tags: Commentary Source Type: research