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| Predicate | Object |
|---|---|
| rdf:type | |
| lifeskim:mentions | |
| pubmed:issue |
4
|
| pubmed:dateCreated |
1997-3-28
|
| pubmed:abstractText |
The properties of the rat brain alpha1E Ca2+ channel subunit and its modulation by accessory rat brain alpha2-delta and beta1b subunits were studied by transient transfection in a mammalian cell line in order to attempt to reconcile the debate as to whether alpha1E forms a low-voltage-activated (LVA) or high-voltage-activated (HVA) Ca2+ channel and to examine its pharmacology in detail. alpha1E alone was capable of forming an ion-conducting pore in COS-7 cells. The properties of heteromultimeric alpha1E/alpha2-delta/beta1b channels were largely dictated by the presence of the beta1b subunit, which increased current density and tended to produce a hyperpolarizing shift in the voltage dependence of activation and inactivation. alpha1E/alpha2-delta/beta1b channels did not appear to be regulated by Ca2+-induced inactivation. alpha1E was shown to exhibit a unique pharmacological profile. omega-Agatoxin IVA blocked the current in a dose-dependent manner with an IC50 of approximately 50 nM and a maximum inhibition of about 80%, whilst omega-conotoxin MVIIC was without effect. The 1,4-dihydropyridine (DHP) antagonist nicardipine (1 micro;M) produced an inhibition of 51 +/- 7%, whereas the DHP agonist S-(-)BAY K 8644 was without effect. Our findings suggest a re-evaluation of the classification of the alpha1E Ca2+ channel subunit; we propose that rat brain alpha1E forms a novel Ca2+ channel with properties more similar to a subtype of LVA than HVA Ca2+ current.
|
| pubmed:grant | |
| 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 |
433
|
| pubmed:owner |
NLM
|
| pubmed:authorsComplete |
Y
|
| pubmed:pagination |
523-32
|
| pubmed:dateRevised |
2009-9-29
|
| pubmed:meshHeading | |
| pubmed:year |
1997
|
| pubmed:articleTitle |
Functional expression of rat brain cloned alpha1E calcium channels in COS-7 cells.
|
| pubmed:affiliation |
Department of Pharmacology, Royal Free Hospital School of Medicine, Rowland Hill Street, London NW3 2PF, UK.
|
| pubmed:publicationType |
Journal Article,
Research Support, Non-U.S. Gov't
|