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| Predicate | Object |
|---|---|
| rdf:type | |
| lifeskim:mentions | |
| pubmed:issue |
1
|
| pubmed:dateCreated |
1984-2-14
|
| pubmed:abstractText |
A comparison was made between the properties of the norepinephrine- and caffeine-sensitive Ca2+ store in both intact and skinned smooth muscle of the rabbit mesenteric artery. After a first application of 10(-5) M norepinephrine, reapplication of norepinephrine did not induce a second contraction in Ca2+-free medium. However, following this sequence 25 mM caffeine still induced a large contraction. The rates of Ca2+ leakage and Ca2+ filling of the norepinephrine-sensitive store were much faster than those of the caffeine-sensitive one. The amplitude of the norepinephrine-induced contraction in Ca2+-free medium also depended on the amount of Ca2+ present in the caffeine-sensitive store. In the saponin-treated skinned muscle caffeine induced a Ca2+ release only after loading with Ca2+, whereas norepinephrine was unable to induce Ca2+ release in the skinned preparation even after loading with Ca2+. The release of Ca2+ from the caffeine-sensitive store could be activated by Ca2+ itself when the skinned muscle was loaded with Ca2+ above 10(-6) M. These results suggest that the norepinephrine-sensitive Ca2+ store is distinct from a large fraction of the caffeine-sensitive one, and that the norepinephrine-sensitive store is close to the cell membrane. In vascular smooth muscle, under physiological conditions, Ca2+ released from the norepinephrine-sensitive store by norepinephrine may induce Ca2+ release from the caffeine-sensitive Ca2+ store which may be comprised of the sarcoplasmic reticulum.
|
| pubmed:language |
eng
|
| pubmed:journal | |
| pubmed:citationSubset |
IM
|
| pubmed:chemical | |
| pubmed:status |
MEDLINE
|
| pubmed:issn |
0303-6847
|
| pubmed:author | |
| pubmed:issnType |
Print
|
| pubmed:volume |
21
|
| pubmed:owner |
NLM
|
| pubmed:authorsComplete |
Y
|
| pubmed:pagination |
43-52
|
| pubmed:dateRevised |
2003-11-14
|
| pubmed:meshHeading |
pubmed-meshheading:6689959-Animals,
pubmed-meshheading:6689959-Caffeine,
pubmed-meshheading:6689959-Calcium,
pubmed-meshheading:6689959-Mesenteric Arteries,
pubmed-meshheading:6689959-Muscle, Smooth, Vascular,
pubmed-meshheading:6689959-Muscle Contraction,
pubmed-meshheading:6689959-Norepinephrine,
pubmed-meshheading:6689959-Rabbits,
pubmed-meshheading:6689959-Saponins
|
| pubmed:year |
1984
|
| pubmed:articleTitle |
Characteristics of the norepinephrine-sensitive Ca2+ store in vascular smooth muscle.
|
| pubmed:publicationType |
Journal Article
|