Linked Life Data

11788419

Source:http://linkedlifedata.com/resource/pubmed/id/11788419

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2002-1-14
pubmed:abstractText
Reactive oxygen species are important modulators of cerebral vascular tone. Recent evidence, mainly from the aorta, suggests that NAD(P)H oxidase is a major source of vascular superoxide. The goal of the present study was to examine the effects of NADH and NADPH that are commonly used to stimulate NAD(P)H oxidase activity, on superoxide levels and cerebral vascular tone. Basilar arteries and cerebral arterioles from normal rabbits were studied in vitro using isolated tissue baths and in vivo using a cranial window, respectively. In the basilar artery, NADH produced a biphasic response; low concentrations (0.1-10 microM NADH) produced marked relaxation, whereas higher concentrations (30-100 microM NADH) produced contraction. Responses to NADH were significantly (P < 0.05) inhibited in the presence of 4,5-dihydroxy-1,3-benzene-disulfonic acid (Tiron; a scavenger of superoxide, 10 mM). In contrast, NADPH (10-100 microM) produced moderate contraction of the basilar artery, which was inhibited in the presence of Tiron. In vivo, NADH produced Tiron-sensitive dilatation of cerebral arterioles. NADH and NADPH dose dependently increased superoxide levels in the basilar artery, as detected by lucigenin (5 microM)-enhanced chemiluminescence, but increases in superoxide were significantly greater for NADPH than NADH. These increases in superoxide were markedly reduced in the presence of polyethylene glycol-superoxide dismutase (300 U/ml) or diphenylene iodonium [0.1 mM, an inhibitor of flavin-containing enzymes, including NAD(P)H oxidase] but were not affected by indomethacin, N(G)-nitro-L-arginine, or allopurinol. These data suggest that NADH- and NADPH-induced changes in cerebral vascular tone are mediated by superoxide, produced by a flavin-containing enzyme, most likely NAD(P)H oxidase, but not xanthine oxidase or nitric oxide synthase.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0363-6135
pubmed:author
pubmed:issnType
Print
pubmed:volume
282
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
H688-95
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
2002
pubmed:articleTitle
Effects of NADH and NADPH on superoxide levels and cerebral vascular tone.
pubmed:affiliation
Department of Internal Medicine, University of Iowa College of Medicine, Iowa City, Iowa 52242, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.