Linked Life Data

16686681

Source:http://linkedlifedata.com/resource/pubmed/id/16686681

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:dateCreated
2006-5-11
pubmed:abstractText
Work is reviewed which provides evidence for the presence of a subsarcolemmal microdomain, in which the [Na(+)] is influenced by Na(+) influx via the Na(+) channel and the activity of the Na pump. The sarcolemma adjacent to this microdomain, which has been referred to as "Na(+) fuzzy space," appears to include Na-Ca exchangers, and thus alterations of [Na(+)] in this space may influence Ca(2+) influx and efflux, and thus Ca(2+) loading, more directly than do alterations of bulk cytoplasmic [Na(+)]. The degree of Ca(2+) loading is an important determinant of contractility in heart muscle, and therefore alterations in fuzzy space [Na(+)] may be important in mediating the positive inotropic effects of Na pump inhibitors, such as digitalis, and the negative inotropic effects of Na(+) channel blockers such as disopyramide. During ischemia, myocyte Ca(2+) overload can contribute to ATP depletion by activation of Ca(2+)-dependent ATPases and by induction of the mitochondrial permeability transition, and thus is an important contributor to myocyte dysfunction and injury. Hypoxia associated with ischemia can induce Na(+) influx via a persistent opening of the Na(+) channel. It is likely that this Na(+) influx elevates [Na(+)] in the fuzzy space, and thus increases Ca(2+) influx via Na-Ca exchange, and increases Ca(2+) loading. Inhibition of the persistent Na(+) current with a resulting decrease in Ca(2+) loading by drugs such as tetrodotoxin (TTX) and ranolazine may be a mechanism by which these agents produce a cardio-protective effect during ischemia.
pubmed:commentsCorrections
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
1045-3873
pubmed:author
pubmed:issnType
Print
pubmed:volume
17 Suppl 1
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
S43-S46
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2006
pubmed:articleTitle
Na"Fuzzy space": does it exist, and is it important in ischemic injury?
pubmed:publicationType
Editorial, Comment, Review, Research Support, Non-U.S. Gov't