Electrolyte transport in the mammalian colon: mechanisms and implications for disease Kunzelmann and Marcus Mall

Kunzelmann, Karl and Mall, Marcus (2002) Electrolyte transport in the mammalian colon: mechanisms and implications for disease Kunzelmann and Marcus Mall. Physiological Reviews, 82 1: 245-289. doi:10.1152/physrev.00026.2001


Author Kunzelmann, Karl
Mall, Marcus
Title Electrolyte transport in the mammalian colon: mechanisms and implications for disease Kunzelmann and Marcus Mall
Journal name Physiological Reviews   Check publisher's open access policy
ISSN 0031-9333
Publication date 2002-01
Sub-type Article (original research)
DOI 10.1152/physrev.00026.2001
Open Access Status
Volume 82
Issue 1
Start page 245
End page 289
Total pages 45
Place of publication Bethesda, MD, United States
Publisher American Physiological Society
Language eng
Subject 270104 Membrane Biology
730113 Digestive system and disorders
Abstract Electrolyte Transport in the Mammalian Colon: Mechanisms and Implications for Disease. Physiol. Rev. 82: 245-289, 2002.The colonic epithelium has both absorptive and secretory functions. The transport is characterized by a net absorption of NaCl, short-chain fatty acids (SCFA), and water, allowing extrusion of a feces with very little water and salt content. In addition, the epithelium does secret mucus, bicarbonate, and KCl. Polarized distribution of transport proteins in both luminal and basolateral membranes enables efficient salt transport in both directions, probably even within an individual cell. Meanwhile, most of the participating transport proteins have been identified, and their function has been studied in detail. Absorption of NaCl is a rather steady process that is controlled by steroid hormones regulating the expression of epithelial Na+ channels (ENaC), the Na+-K+-ATPase, and additional modulating factors such as the serum- and glucocorticoid-regulated kinase SGK. Acute regulation of absorption may occur by a Na+ feedback mechanism and the cystic fibrosis transmembrane conductance regulator (CFTR). Cl- secretion in the adult colon relies on luminal CFTR, which is a cAMP-regulated Cl- channel and a regulator of other transport proteins. As a consequence, mutations in CFTR result in both impaired Cl- secretion and enhanced Na+ absorption in the colon of cystic fibrosis (CF) patients. Ca2+- and cAMP-activated basolateral K+ channels support both secretion and absorption of electrolytes and work in concert with additional regulatory proteins, which determine their functional and pharmacological profile. Knowledge of the mechanisms of electrolyte transport in the colon enables the development of new strategies for the treatment of CF and secretory diarrhea. It will also lead to a better understanding of the pathophysiological events during inflammatory bowel disease and development of colonic carcinoma.
Q-Index Code CX

Document type: Journal Article
Sub-type: Article (original research)
Collection: School of Biological Sciences Publications
 
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Created: Thu, 23 Aug 2007, 14:35:20 EST