Linked Life Data

16678494

Source:http://linkedlifedata.com/resource/pubmed/id/16678494

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2006-9-18
pubmed:abstractText
This study was undertaken to investigate the effect of euxanthone on isolated rat thoracic aorta. Euxanthone concentration-dependently relaxed high K+-induced sustained contractions with IC50 values of 32.28+/-1.73 microM and this inhibition was antagonized by increasing the Ca2+ concentration in the medium. These results indicated that euxanthone may have calcium antagonistic property. Euxanthone also relaxed norepinephrine (NE)-induced sustained contractions with IC50 values of 32.50+/-2.15 microM and this relaxant effect was unaffected by the removal of endothelium or by the presence of propranolol, indomethacin, glibenclamide or N(omega)-nitro-L-arginine. Moreover, euxanthone inhibited both the phasic and tonic contractions induced by NE in a concentration-dependent manner and showed more potent inhibition on phasic contraction (P < 0.01). Pre-treatment with euxanthone inhibited vascular contraction induced by phorbol 12, 13-dibutyrate (PDBu), a protein kinase C (PKC) agonist, in either the presence or absence of Ca2+ in the solution with IC50 values of 20.15+/-1.56 and 18.30+/-1.62 microM, respectively. However, when the tissues were treated with euxanthone after the PDBu-induced contraction had reached a steady state, the tension was not affected by euxanthone. This study also showed that the inhibitory effect of pre-treatment of euxanthone was more potent than the post-treatment after the tension had reached a steady state. These results suggested that the vasorelaxation of euxanthone may be through multiple pathways involved PKC-mediated signal pathway and calcium-independent pathway besides the direct inhibition of calcium influx and its vasorelaxant effect is more active on calcium-independent pathway and more sensitive to the initial stage of contraction.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
1537-1891
pubmed:author
pubmed:issnType
Print
pubmed:volume
45
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
96-101
pubmed:meshHeading
pubmed:year
2006
pubmed:articleTitle
Vasorelaxant effect of euxanthone in the rat thoracic aorta.
pubmed:affiliation
Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't