Linked Life Data

11404275

Source:http://linkedlifedata.com/resource/pubmed/id/11404275

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2001-6-13
pubmed:abstractText
Diesel exhaust particles cause an impairment of endothelium-dependent vasorelaxation and are associated with cardiopulmonary-related diseases and mortality, but the mechanistic details are poorly understood. Since we reported previously that phenanthraquinone, an environmental chemical contained in diesel exhaust particles, suppresses neuronal nitric oxide synthase (nNOS) activity by shunting electrons away from the normal catalytic pathway, it was hypothesized that phenanthraquinone inhibits endothelial NOS (eNOS) activity and affects vascular tone. Therefore, the effects of phenanthraquinone on eNOS activity, endothelium-dependent relaxation, and blood pressure were examined in the present study. Phenanthraquinone inhibited NO formation evaluated by citrulline formed by total membrane fraction of bovine aortic endothelial cells with an IC(50) value of 0.6 microM. A kinetic study revealed that phenanthraquinone is a competitive inhibitor with respect to NADPH and a noncompetitive inhibitor with respect to L-arginine. Endothelium-dependent relaxation of rat aortic rings by ACh was significantly inhibited by phenanthraquinone (5 microM), whereas the endothelium-independent relaxation by nitroglycerin was not. Furthermore, an intraperitoneal injection of phenanthraquinone (0.36 mmol/kg) to rats resulted in an elevation of blood pressure (1.4-fold, P < 0.01); under this condition, plasma levels of stable NO metabolites, nitrite/nitrate, in phenanthraquinone-treated rats was reduced to 68% of control levels. The present findings suggest that phenanthraquinone has a potent inhibitory action on eNOS activity via a similar mechanism reported for nNOS, thereby causing the suppression of NO-mediated vasorelaxation and elevation of blood pressure.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0363-6119
pubmed:author
pubmed:issnType
Print
pubmed:volume
281
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
R25-30
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2001
pubmed:articleTitle
Phenanthraquinone inhibits eNOS activity and suppresses vasorelaxation.
pubmed:affiliation
Department of Environmental Medicine, Institute of Community Medicine, Cardiovascular Division, Institute of Clinical Medicine, University of Tsukuba, Tsukuba, Ibaraki 305-8575, Japan. yk-em-tu@md.tsukuba.ac.jp
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't