Source:http://linkedlifedata.com/resource/pubmed/id/16455108
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| Predicate | Object |
|---|---|
| rdf:type | |
| lifeskim:mentions | |
| pubmed:issue |
1
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| pubmed:dateCreated |
2006-5-22
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| pubmed:abstractText |
The present study examines possible mechanisms by which the flavonoid isokaempferide (IKPF; 5,7,4'-trihydroxy-3-methoxyflavone) from Amburana cearensis, a Brazilian medicinal plant popularly used as bronchodilator, induces relaxation of guinea-pig isolated trachea. In the trachea (with intact epithelium) contracted by carbachol, IKPF (1-1000 microM) caused a graded relaxation, and the epithelium removal increased the sensitivity of the airway smooth muscle to IKPF (EC50, in intact tissue: 77.4 [54.8-109.2] microM; in denuded epithelium: 15.0 [11.3-20.1] microM). The IKPF-induced relaxation was inhibited in 41% by the nitric oxide (NO) synthase inhibitor L-NAME (100 microM); in 31% and 50% by the soluble guanylate cyclase (sGC) inhibitor ODQ (3 and 33 microM); by propranolol (31%) and also by capsaicin (37%). In the trachea pre-contracted by 40 mM KCl the pre-incubation with glibenclamide (33 microM) or iberiotoxin (IbTX, 0.1 microM), selective K(+) channel inhibitors, inhibited the IKPF-induced relaxation by 39% and 38%, respectively. On the other hand, 4-aminopyridine (100 microM), a nonselective K(+) channel antagonist, did not significantly influence the effect of IKPF, while IbTX induced a rightward displacement of the IKPF concentration-response curve. However, in muscle pre-contracted with 120 mM KCl the relaxant effect of IKPF was significantly reduced and not affected by glibenclamide. In conclusion, these results indicate a direct and epithelium-independent relaxant effect of IKPF on smooth muscle fibers. Although this IKPF relaxant action seems to be multi-mediated, it occurs via both Ca(2+) and ATP-sensitive K(+) channels, but some other possible mechanisms unrelated to K(+) channels cannot be excluded.
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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/Adrenergic beta-Antagonists,
http://linkedlifedata.com/resource/pubmed/chemical/Capsaicin,
http://linkedlifedata.com/resource/pubmed/chemical/Carbachol,
http://linkedlifedata.com/resource/pubmed/chemical/Coumarins,
http://linkedlifedata.com/resource/pubmed/chemical/Enzyme Inhibitors,
http://linkedlifedata.com/resource/pubmed/chemical/Flavonoids,
http://linkedlifedata.com/resource/pubmed/chemical/Guanylate Cyclase,
http://linkedlifedata.com/resource/pubmed/chemical/Histamine,
http://linkedlifedata.com/resource/pubmed/chemical/Muscarinic Agonists,
http://linkedlifedata.com/resource/pubmed/chemical/NG-Nitroarginine Methyl Ester,
http://linkedlifedata.com/resource/pubmed/chemical/Plant Extracts,
http://linkedlifedata.com/resource/pubmed/chemical/Potassium Channel Blockers,
http://linkedlifedata.com/resource/pubmed/chemical/Potassium Chloride,
http://linkedlifedata.com/resource/pubmed/chemical/coumarin
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| pubmed:status |
MEDLINE
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| pubmed:month |
May
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| pubmed:issn |
0024-3205
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| pubmed:author | |
| pubmed:issnType |
Print
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| pubmed:day |
30
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| pubmed:volume |
79
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| pubmed:owner |
NLM
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| pubmed:authorsComplete |
Y
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| pubmed:pagination |
98-104
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| pubmed:dateRevised |
2006-11-15
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| pubmed:meshHeading |
pubmed-meshheading:16455108-Adrenergic beta-Antagonists,
pubmed-meshheading:16455108-Animals,
pubmed-meshheading:16455108-Capsaicin,
pubmed-meshheading:16455108-Carbachol,
pubmed-meshheading:16455108-Coumarins,
pubmed-meshheading:16455108-Enzyme Inhibitors,
pubmed-meshheading:16455108-Flavonoids,
pubmed-meshheading:16455108-Guanylate Cyclase,
pubmed-meshheading:16455108-Guinea Pigs,
pubmed-meshheading:16455108-Histamine,
pubmed-meshheading:16455108-Muscarinic Agonists,
pubmed-meshheading:16455108-Muscle, Smooth,
pubmed-meshheading:16455108-Muscle Relaxation,
pubmed-meshheading:16455108-NG-Nitroarginine Methyl Ester,
pubmed-meshheading:16455108-Plant Bark,
pubmed-meshheading:16455108-Plant Extracts,
pubmed-meshheading:16455108-Plants,
pubmed-meshheading:16455108-Potassium Channel Blockers,
pubmed-meshheading:16455108-Potassium Chloride,
pubmed-meshheading:16455108-Trachea
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| pubmed:year |
2006
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| pubmed:articleTitle |
Mechanisms underlying the relaxation induced by isokaempferide from Amburana cearensis in the guinea-pig isolated trachea.
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| pubmed:affiliation |
Department of Pharmacy, Federal University of Ceará, Fortaleza, Brazil. kalyne@ufc.br
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| pubmed:publicationType |
Journal Article,
In Vitro,
Research Support, Non-U.S. Gov't
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