Linked Life Data

2379949

Source:http://linkedlifedata.com/resource/pubmed/id/2379949

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1990-9-10
pubmed:abstractText
We studied the mechanism of the vasodilator effect of H2O2 on cerebral arterioles and its effect on endothelium-dependent responses to acetylcholine. Topical application of H2O2 (0.1-1 microM) on the brain surface of anesthetized cats equipped with cranial windows induced dose-dependent arteriolar dilation, which was markedly inhibited by topical deferoxamine, showing that it was probably mediated by generation of hydroxyl radical. Higher concentrations of H2O2 (3 microM) also induced dilation, which was unaffected by deferoxamine, indicating the participation of other mechanisms. After topical application of H2O2, endothelium-dependent responses to acetylcholine were eliminated or converted to vasoconstriction, and in bioassay experiments, acetylcholine-mediated endothelium-derived relaxing factor (EDRF) was absent. Superoxide dismutase plus catalase restored the appearance of transferable EDRF after 1 microM H2O2 but not after 3 microM H2O2. Application of H2O2 in the assay window eliminated the responses to nitroprusside and nitric oxide but did not affect responses to adenosine, to EDRF from the donor window, or responses to S-nitroso-L-cysteine. The inhibiting effect of H2O2 on the response to nitroprusside was partially eliminated after topical application of N-acetyl-L-cysteine. The results show that H2O2 inhibits the vasodilator action of nitroprusside and nitric oxide probably because it oxidizes thiols in vascular smooth muscle and prevents the formation of a nitrosothiol. EDRF from acetylcholine and S-nitroso-L-cysteine still produce dilation in the presence of the blockade induced by H2O2. The findings suggest strongly that the EDRF from acetylcholine in cerebral vessels is a nitrosothiol like S-nitroso-L-cysteine.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0194-911X
pubmed:author
pubmed:issnType
Print
pubmed:volume
16
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
162-9
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1990
pubmed:articleTitle
H2O2 and endothelium-dependent cerebral arteriolar dilation. Implications for the identity of endothelium-derived relaxing factor generated by acetylcholine.
pubmed:affiliation
Department of Medicine, Medical College of Virginia, Richmond 23298.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.