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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
2003-4-4
pubmed:abstractText
We previously cloned Na(+)/Ca(2+) exchanger (NCX1) from mesangial cells of salt-sensitive (SNCX = NCX1.7) and salt-resistant (RNCX = NCX1.3) Dahl/Rapp rats. The abilities of these isoforms to regulate cytosolic Ca(2+) concentration ([Ca(2+)](i)) were assessed in fura 2-loaded OK cells expressing the vector (VOK), RNCX (ROK), and SNCX (SOK). Baseline [Ca(2+)](i) was 98 +/- 20 nM (n = 12) in VOK and was significantly lower in ROK (44 +/- 5 nM; n = 12) and SOK (47 +/- 13 nM; n = 12) cells. ATP at 100 microM increased [Ca(2+)](i) by 189 +/- 55 nM (n = 12), 21 +/- 9 nM (n = 12), and 69 +/- 18 nM (n = 12) in VOK, ROK, and SOK cells, respectively. ATP (1 mM) or bradykinin (0.1 mM) caused large increases in [Ca(2+)](i) and ROK but not SOK cells were much more efficient in reducing [Ca(2+)](i) back to baseline levels. Parental Sprague-Dawley rat mesangial cells express both RNCX (SDRNCX) and SNCX (SDSNCX). SDRNCX and RNCX are identical at every amino acid residue, but SDSNCX and SNCX differ at amino acid 218 where it is isoleucine in SDSNCX and not phenylalanine. OK cells expressing SDSNCX (SDSOK) reduced ATP (1 mM)-induced [Ca(2+)](i) increase back to baseline at a rate equivalent to that for ROK cells. PKC downregulation significantly attenuated the rate at which ROK and SDSOK cells reduced ATP-induced [Ca(2+)](i) increase but had no effect in SOK cells. The reduced efficiency of SNCX to regulate [Ca(2+)](i) is attributed, in part, to the isoleucine-to-phenylalanine mutation at amino acid 218.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
1931-857X
pubmed:author
pubmed:issnType
Print
pubmed:volume
284
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
F1023-31
pubmed:dateRevised
2011-4-28
pubmed:meshHeading
pubmed-meshheading:12527551-Amino Acid Sequence, pubmed-meshheading:12527551-Animals, pubmed-meshheading:12527551-Base Sequence, pubmed-meshheading:12527551-Buffers, pubmed-meshheading:12527551-Calcium, pubmed-meshheading:12527551-Cells, Cultured, pubmed-meshheading:12527551-Cytosol, pubmed-meshheading:12527551-DNA, pubmed-meshheading:12527551-Enzyme Activation, pubmed-meshheading:12527551-Genome, pubmed-meshheading:12527551-Kidney Tubules, Proximal, pubmed-meshheading:12527551-Opossums, pubmed-meshheading:12527551-Osmolar Concentration, pubmed-meshheading:12527551-Protein Isoforms, pubmed-meshheading:12527551-Protein Kinase C, pubmed-meshheading:12527551-Rats, pubmed-meshheading:12527551-Rats, Inbred Dahl, pubmed-meshheading:12527551-Rats, Sprague-Dawley, pubmed-meshheading:12527551-Sodium-Calcium Exchanger, pubmed-meshheading:12527551-Time Factors
pubmed:year
2003
pubmed:articleTitle
Impaired ability of the Na+/Ca2+ exchanger from the Dahl/Rapp salt-sensitive rat to regulate cytosolic calcium.
pubmed:affiliation
Nephrology Research and Training Center, Department of Medicine, Division of Nephrology, University of Alabama at Birmingham, Alabama 35294, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't