Linked Life Data

8782061

Source:http://linkedlifedata.com/resource/pubmed/id/8782061

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
1996-11-27
pubmed:abstractText
Hyperkalemic cardioplegic solutions produce cardiac arrest during open heart surgery by depolarizing the sarcolemma. A recognized adverse effect of hyperkalemic cardioplegia is the possible development of ventricular dysfunction believed to be related to intracellular Ca2+ loading, a consequence of K(+)-induced membrane depolarization. Adenosine has been proposed as an adjunct to hyperkalemic cardioplegic solutions. However, it is not known whether adenosine can affect K(+)-induced membrane depolarization, and associated intracellular Ca2+ loading. Perforated patch-clamp method, applied to isolated single guinea-pig ventricular myocytes, revealed that adenosine (1 mM) did not significantly reduce the magnitude of K(+)-induced membrane depolarization (35.7 +/- 1.7 v 31.0 +/- 1.1 mV in the absence v presence of adenosine). Yet, adenosine significantly slowed the rate of K(+)-induced membrane depolarization (167 +/- 32.8 v 67.9 +/- 12.9 mV/min in the absence v presence of adenosine) without directly affecting Ca2+, Na+, and K+ currents. Imposed ramp-pulses, with different rates (ranging from 0.33 to 0.05 V/s), but same magnitude of depolarization (100 mV), demonstrated that reduction in the rate of membrane depolarization decreases net inward Ca2+ current. Indeed, in Fluo-3 loaded ventricular myocytes, imaged by laser confocal microscopy, adenosine (1 mM) prevented K(+)-induced intracellular Ca2+ loading. The present findings indicate that adenosine slows the rate of K(+)-induced membrane depolarization, and reduces K(+)-induced intracellular Ca2+ loading in ventricular myocytes. Such findings support the notion that adenosine may play a cardioprotective role in hyperkalemic cardioplegia.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0022-2828
pubmed:author
pubmed:issnType
Print
pubmed:volume
28
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1193-202
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1996
pubmed:articleTitle
Adenosine slows the rate of K(+)-induced membrane depolarization in ventricular cardiomyocytes: possible implication in hyperkalemic cardioplegia.
pubmed:affiliation
Departments of Medicine and Pharmacology, Mayo Clinic, Rochester, MN, USA.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't