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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1998-2-26
pubmed:abstractText
We have found previously that run-down of cardiac Ca2+ channels in cell-free patches is reversed by cytoplasm plus adenosine triphosphate (ATP). Characterization of the factor in cytoplasm revealed that it is likely to be calpastatin (CS), an endogenous inhibitor of calpain (Ca2+-activated neutral protease). We therefore investigated the possible restoring effect of CS obtained from various tissues (activity 1.3-23 U/ml) on Ca2+ channel activity after run-down in inside-out patches. Although CS from porcine erythrocytes (plus 3 mM ATP) had only a minimal effect in restoring channel activity (to 4% of the control level recorded before the run-down), CS from porcine heart restored channel activity to 19% of control. The product of recombinant complementary deoxyribonucleic acid (cDNA) of human heart CS, a membrane-bound CS partially purified from bovine heart and CS from rabbit skeletal muscle (Sigma) restored channel activity to 28%, 23% and 10% of control levels, respectively. These results suggest that tissue-type CS, but not erythrocyte-type (truncated) CS, seems to have an effect on the cardiac Ca2+ channel to maintain its activity. Purified CS had relatively small effects compared to that of crude cytoplasm, implying that some other factor(s) might contribute also to the regulation of Ca2+ channel activity.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0031-6768
pubmed:author
pubmed:issnType
Print
pubmed:volume
435
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
344-9
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed-meshheading:9426288-Adenosine Triphosphate, pubmed-meshheading:9426288-Animals, pubmed-meshheading:9426288-Calcium Channels, pubmed-meshheading:9426288-Calcium-Binding Proteins, pubmed-meshheading:9426288-Calpain, pubmed-meshheading:9426288-Cattle, pubmed-meshheading:9426288-Cytoplasm, pubmed-meshheading:9426288-Erythrocytes, pubmed-meshheading:9426288-Guinea Pigs, pubmed-meshheading:9426288-Heart Ventricles, pubmed-meshheading:9426288-Humans, pubmed-meshheading:9426288-Molecular Weight, pubmed-meshheading:9426288-Muscle, Skeletal, pubmed-meshheading:9426288-Myocardium, pubmed-meshheading:9426288-Organ Specificity, pubmed-meshheading:9426288-Patch-Clamp Techniques, pubmed-meshheading:9426288-Rabbits, pubmed-meshheading:9426288-Recombinant Proteins, pubmed-meshheading:9426288-Species Specificity, pubmed-meshheading:9426288-Swine
pubmed:year
1998
pubmed:articleTitle
Run-down of the cardiac L-type Ca2+ channel: partial restoration of channel activity in cell-free patches by calpastatin.
pubmed:affiliation
Department of Physiology, Faculty of Medicine, Kagoshima University, Kagoshima 890, Japan.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't