Document Detail


In vitro potassium transport in the mouse small intestine.
MedLine Citation:
PMID:  12617757     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Ingested K+ is believed to be absorbed mainly in the small intestine by passive diffusion through the paracellular pathway. To further clarify K+ absorption in the small intestine, we determined the unidirectional flux values of Rb+ in vitro by atomic absorption spectroscopy in the mouse ileum mounted in Ussing chambers under short-circuit conditions. The mucosal-to-serosal Rb+ flux (J(ms)) was larger than the serosal-to-mucosal Rb+ flux (J(sm)), resulting in positive net Rb+ absorption (J(net)). The effect of changing the transmucosal potential (V(t)) showed that J(ms) was composed of both a V(t)-dependent diffusion component and a V(t)-independent non-diffusion component, while J(sm) was composed mainly of a V(t)-dependent component. A forskolin treatment eliminated J(net) mainly due to the increase in J(sm). When animals were fed a low-Na diet, J(net) was mainly eliminated as a result of the increase in J(sm). These findings suggest that K+ is absorbed not only by passive diffusion through the paracellular pathway, but also by an active transport mechanism operating through the cellular pathway. In addition, cAMP and aldosterone may be involved in regulating intestinal K+ transport.
Authors:
Eiko Inagaki; Koichi Kawamata; Yuichi Suzuki
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  The Japanese journal of physiology     Volume:  52     ISSN:  0021-521X     ISO Abbreviation:  Jpn. J. Physiol.     Publication Date:  2002 Dec 
Date Detail:
Created Date:  2003-03-05     Completed Date:  2003-11-20     Revised Date:  2007-03-21    
Medline Journal Info:
Nlm Unique ID:  2985184R     Medline TA:  Jpn J Physiol     Country:  Japan    
Other Details:
Languages:  eng     Pagination:  515-20     Citation Subset:  IM    
Affiliation:
Laboratory of Physiology, School of Food and Nutritional Sciences, University of Shizuoka, Shizuoka, 422-8526 Japan. e-ina@nuas.ac.jp
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MeSH Terms
Descriptor/Qualifier:
Adsorption
Animals
Cell Membrane / drug effects,  metabolism*
Culture Techniques
Forskolin / pharmacology
Ileum / drug effects,  metabolism*
Intestine, Small / metabolism
Male
Membrane Potentials / drug effects,  physiology*
Mice
Potassium / pharmacokinetics*
Rubidium / pharmacokinetics*
Sodium / deficiency
Chemical
Reg. No./Substance:
66428-89-5/Forskolin; 7440-09-7/Potassium; 7440-17-7/Rubidium; 7440-23-5/Sodium

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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