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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
1-2
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pubmed:dateCreated |
1997-9-16
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pubmed:abstractText |
To examine the mechanisms involved in cerebrospinal fluid (CSF) K+ homeostasis, lateral ventricle choroid plexuses were isolated from rats fed low, normal or high K+ diets for 2 weeks. Potassium (86Rb) influx and efflux were then examined in vitro. Dietary hypo- and hyperkalemia (2.8 +/- 0.1 and 6.8 +/- 0.3 mM) did not affect the efflux rate constant for 86Rb or the influx rate constant in the absence of inhibitors. However, the ouabain-sensitive portion of influx was only 1.9 +/- 0.5 microl/g per min in plexuses from hypokalemic rats compared to 4.5 +/- 0.5 microl/g/min in controls (P < 0.001). This change in Na+/K+-ATPase activity was reflected in an increasing amount (Western blot) of the alpha1 and beta1 subunits of this pump with increasing plasma K+ concentration (P < 0.05) whereas the beta2 subunit was unaffected. The other known choroid plexus K+ uptake mechanism, bumetanide-sensitive K+ cotransport, was unaffected by dietary K+ manipulation. In normo- and hyperkalemic rats, the sum of the ouabain- and bumetanide-sensitive fluxes could account for all of 86Rb uptake. However, in hypokalemic rats a major component (40%) of uptake could not be accounted for by either mechanism. This unidentified mechanism may be a basolateral uptake mechanism involved in increasing K+ transport from blood to CSF during hypokalemia.
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pubmed:grant | |
pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
IM
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pubmed:chemical | |
pubmed:status |
MEDLINE
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pubmed:month |
May
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pubmed:issn |
0006-8993
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:day |
30
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pubmed:volume |
758
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
39-44
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pubmed:dateRevised |
2007-11-14
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pubmed:meshHeading |
pubmed-meshheading:9203531-Animals,
pubmed-meshheading:9203531-Biological Transport,
pubmed-meshheading:9203531-Choroid Plexus,
pubmed-meshheading:9203531-Hyperkalemia,
pubmed-meshheading:9203531-Hypokalemia,
pubmed-meshheading:9203531-Male,
pubmed-meshheading:9203531-Potassium,
pubmed-meshheading:9203531-Rats,
pubmed-meshheading:9203531-Rats, Sprague-Dawley
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pubmed:year |
1997
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pubmed:articleTitle |
The effects of hypo- and hyperkalemia on choroid plexus potassium transport.
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pubmed:affiliation |
Department of Surgery (Neurosurgery), University of Michigan, Ann Arbor 48109-0532, USA.
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pubmed:publicationType |
Journal Article,
Research Support, U.S. Gov't, P.H.S.
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