Linked Life Data

15345496

Source:http://linkedlifedata.com/resource/pubmed/id/15345496

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
2004-9-3
pubmed:abstractText
We investigated the involvement of intracellular and extracellular Ca2+ in the stimulation of Na+ transport during hyposmotic treatment of A6 renal epithelia. A sudden osmotic decrease elicits a biphasic stimulation of Na+ transport, recorded as increase in amiloride-sensitive short-circuit current (Isc) from 3.4 +/- 0.4 to 24.0 +/- 1.3 microA/cm2 (n = 6). Changes in intracellular Ca2+ concentration ([Ca2+]i) were prevented by blocking basolateral Ca2+ entry with Mg2+ and emptying the intracellular Ca2+ stores before the hyposmotic challenge. This treatment did not noticeably affect the hypotonicity-induced stimulation of Isc. However, the absence of extracellular Ca2+ severely attenuated Na+ transport stimulation by the hyposmotic shock, and Isc merely increased from 2.2 +/- 0.3 to 4.8 +/- 0.7 microA/cm2. Interestingly, several agonists of the Ca2+-sensing receptor, Mg2+ (2 mM), Gd3+ (0.1 mM), neomycin (0.1 mM), and spermine (1 mM) were able to substitute for extracellular Ca2+. When added to the basolateral solution, these agents restored the stimulatory effect of the hyposmotic solutions on Isc in the absence of extracellular Ca2+ to levels that were comparable to control conditions. None of the above-mentioned agonists induced a change in [Ca2+]i. Quinacrine, an inhibitor of PLA2, overruled the effect of the agonists on Na+ transport. In conclusion, we suggest that a Ca2+-sensing receptor in A6 epithelia mediates the stimulation of Na+ transport without the interference of changes in [Ca2+]i.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
1931-857X
pubmed:author
pubmed:issnType
Print
pubmed:volume
287
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
F840-9
pubmed:dateRevised
2011-4-28
pubmed:meshHeading
pubmed:year
2004
pubmed:articleTitle
Extracellular Ca2+ regulates the stimulation of Na+ transport in A6 renal epithelia.
pubmed:affiliation
Laboratory of Physiology, Biomedical Research Institute, Limburgs Universitair Centrum, Universitaire Campus, B-3590 Diepenbeek, Belgium.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't