Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2004-12-21
pubmed:abstractText
Erythrocyte magnesium (Mg2+) deficiency has been demonstrated in sickle cell disease to contribute to erythrocyte dehydration, K loss, and thus sickling. No studies have assessed the functional properties of the Na/Mg exchanger in sickle cell disease. Using Mg(2+)-loaded erythrocytes, we measured Mg2+ efflux induced by extracellular Na+. We estimated that the Na/Mg exchanger had higher maximal velocity, higher affinity for Na+, and lower cooperativity for Mg2+ in sickle than in normal erythrocytes. The activity of the exchanger was markedly decreased by hypotonic and hypertonic conditions in normal erythrocytes but not in sickle erythrocytes. Studies of density-separated erythrocytes showed that the activity of the exchanger decreased as the mean cellular hemoglobin concentration increased in normal but not in sickle erythrocytes. Inhibition of protein kinase C (PKC) activity by calphostin C and chelerythrine increased the activity of the exchanger in normal but not in sickle erythrocytes. Inhibition of serine/threonine phosphatases did not affect the activity of the exchanger in either normal or sickle erythrocytes. Altogether, these data indicate that the Na/Mg exchanger is abnormally regulated in sickle erythrocytes. Therefore, Mg2+ depletion in sickle erythrocytes might be mediated by an up-regulated Na/Mg exchanger, possibly by dephosphorylation of the transporter or a closely associated regulator.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0006-4971
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
105
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
382-6
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed:year
2005
pubmed:articleTitle
Abnormal regulation of Mg2+ transport via Na/Mg exchanger in sickle erythrocytes.
pubmed:affiliation
Department of Laboratory Medicine, Children's Hospital Boston, Boston, MA 02115, USA. alicia.rivera@childrens.harvard.edu
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.