Linked Life Data

2589492

Source:http://linkedlifedata.com/resource/pubmed/id/2589492

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5 Pt 2
pubmed:dateCreated
1989-12-28
pubmed:abstractText
Rapid cooling contractures (RCCs) were used to assess changes in sarcoplasmic reticulum (SR) Ca content in both isolated rabbit ventricular myocytes and multicellular preparations. The main difference observed between these preparations was the magnitude of RCCs relative to twitches, apparently due to differences in measured parameters, i.e., unloaded shortening vs. isometric tension. When multicellular preparations were unloaded, RCC shortening was similar to that observed in myocytes. RCC magnitude decreased as the time between the last electrical stimulation and the RCC was increased (rest decay). RCC rest decay closely paralleled that of postrest twitches, suggesting that SR Ca loss is responsible for this process. Paired RCC experiments were used to investigate RCC relaxation and rest decay. When a second RCC (RCC2) was induced immediately after the first (RCC1), a large contracture was still observed (RCC2/RCC1 x 100 = 77.8 +/- 7.3%, mean +/- SD), indicating that the SR resequestered the majority of Ca on rewarming. This fraction was increased (to 92.9 +/- 5.5%) if Na and Ca-free solution was used during RCCs and rewarming, indicating that Na-Ca exchange also contributes to RCC relaxation. Increasing the interval between paired RCCs led to a decrease in RCC2, analogous to rest decay. This rest decay was abolished by inhibiting Na-Ca exchange, indicating that SR Ca loss during rest is mediated primarily by this process. RCCs were abolished by 10 mM caffeine. Ryanodine (1 microM) greatly accelerated RCC rest decay but had less effect on RCCs generated immediately after a train of stimulation. This accelerated rest decay was also dependent on Na-Ca exchange.(ABSTRACT TRUNCATED AT 250 WORDS)
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0002-9513
pubmed:author
pubmed:issnType
Print
pubmed:volume
257
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
H1369-77
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
1989
pubmed:articleTitle
Rapid cooling contractures as an index of sarcoplasmic reticulum calcium content in rabbit ventricular myocytes.
pubmed:affiliation
Division of Biomedical Sciences, University of California, Riverside 92521-0121.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't