Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
30
pubmed:dateCreated
2001-7-23
pubmed:abstractText
We investigated the cellular and molecular mechanisms underlying arrhythmias in heart failure. A genetically engineered mouse lacking the expression of the muscle LIM protein (MLP-/-) was used in this study as a model of heart failure. We used electrocardiography and patch clamp techniques to examine the electrophysiological properties of MLP-/- hearts. We found that MLP-/- myocytes had smaller Na+ currents with altered voltage dependencies of activation and inactivation and slower rates of inactivation than control myocytes. These changes in Na+ currents contributed to longer action potentials and to a higher probability of early afterdepolarizations in MLP-/- than in control myocytes. Western blot analysis suggested that the smaller Na+ current in MLP-/- myocytes resulted from a reduction in Na+ channel protein. Interestingly, the blots also revealed that the alpha-subunit of the Na+ channel from the MLP-/- heart had a lower average molecular weight than in the control heart. Treating control myocytes with the sialidase neuraminidase mimicked the changes in voltage dependence and rate of inactivation of Na+ currents observed in MLP-/- myocytes. Neuraminidase had no effect on MLP-/- cells thus suggesting that Na+ channels in these cells were sialic acid-deficient. We conclude that deficient glycosylation of Na+ channel contributes to Na+ current-dependent arrhythmogenesis in heart failure.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
27
pubmed:volume
276
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
28197-203
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed:year
2001
pubmed:articleTitle
Role of sodium channel deglycosylation in the genesis of cardiac arrhythmias in heart failure.
pubmed:affiliation
Institute of Neurobiology, University of Puerto Rico, San Juan, Puerto Rico 00901, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S.