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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
1
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pubmed:dateCreated |
1988-8-17
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pubmed:abstractText |
In rat aortic strips, muscle contraction was recorded simultaneously with cytosolic Ca++ level, which was indicated by the 500 nm fluorescence of Ca++ indicator, fura 2, due to excitation at either 340 nm (F340) or 380 nm (F380) and the ratio of F340 to F380 (R340/380). On the addition of 72.7 nM K+ or 1 microM norepinephrine, muscle contraction followed the increase in R340/380 (resulted from the increased F340 and the decreased F380). Cytosolic Ca++ concentrations of resting, 72.7 mM K+-stimulated and 1 microM norepinephrine-stimulated aortas were tentatively calculated as 228 +/- 25, 1784 +/- 154 and 1528 +/- 180 nM, respectively. Cumulative addition of K+ or norepinephrine induced concentration-dependent increase in both muscle tension and R340/380. However, norepinephrine induced greater contraction than K+ when both of these stimulants induced similar increase in R340/380. Addition of 10 mM tetraethylammonium and 1 microM Bay k8644 caused rhythmic contractions which followed the rhythmic changes in R340/380. EGTA decreased the muscle contraction and decreased R340/380. In Ca++-free solution, addition of 10 microM norepinephrine or 20 mM caffeine induced transient increase in both muscle tension and R340/380. Tension changes always were preceded by the fluorescent changes. Verapamil (10 microM) decreased both tension development and R340/380 in high K+- and norepinephrine-stimulated tissues. Sodium nitroprusside (1 microM) also decreased both tension and R340/380 in norepinephrine-stimulated tissues, whereas it decreased tension more strongly than R340/380 in high K+-stimulated tissues. These results indicate that vasoconstrictors and vasodilators may modulate smooth muscle contraction by changing the cytosolic Ca++ concentrations and also by changing the sensitivity of contractile elements to Ca++.
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pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
IM
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pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/3-Pyridinecarboxylic acid...,
http://linkedlifedata.com/resource/pubmed/chemical/Benzofurans,
http://linkedlifedata.com/resource/pubmed/chemical/Calcium,
http://linkedlifedata.com/resource/pubmed/chemical/Fura-2,
http://linkedlifedata.com/resource/pubmed/chemical/Norepinephrine,
http://linkedlifedata.com/resource/pubmed/chemical/Potassium,
http://linkedlifedata.com/resource/pubmed/chemical/Tetraethylammonium Compounds
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pubmed:status |
MEDLINE
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pubmed:month |
Jul
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pubmed:issn |
0022-3565
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:volume |
246
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
294-300
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pubmed:dateRevised |
2006-11-15
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pubmed:meshHeading |
pubmed-meshheading:2455792-3-Pyridinecarboxylic acid...,
pubmed-meshheading:2455792-Animals,
pubmed-meshheading:2455792-Benzofurans,
pubmed-meshheading:2455792-Calcium,
pubmed-meshheading:2455792-Cytosol,
pubmed-meshheading:2455792-Fura-2,
pubmed-meshheading:2455792-Male,
pubmed-meshheading:2455792-Muscle, Smooth, Vascular,
pubmed-meshheading:2455792-Muscle Contraction,
pubmed-meshheading:2455792-Norepinephrine,
pubmed-meshheading:2455792-Potassium,
pubmed-meshheading:2455792-Rats,
pubmed-meshheading:2455792-Rats, Inbred Strains,
pubmed-meshheading:2455792-Tetraethylammonium Compounds
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pubmed:year |
1988
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pubmed:articleTitle |
Changes in cytosolic calcium level in vascular smooth muscle strip measured simultaneously with contraction using fluorescent calcium indicator fura 2.
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pubmed:affiliation |
Department of Veterinary Pharmacology, Faculty of Agriculture, University of Tokyo, Japan.
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pubmed:publicationType |
Journal Article,
Research Support, Non-U.S. Gov't
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