Linked Life Data

9838199

Source:http://linkedlifedata.com/resource/pubmed/id/9838199

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1999-1-5
pubmed:abstractText
The interaction between nitric oxide (NO) and adrenergic reactivity in the cerebral circulation was studied using in vivo and in vitro preparations. Blood flow to one brain hemisphere (cerebral blood flow) was electromagnetically measured in conscious goats, and the effects of norepinephrine, tyramine and cervical sympathetic nerve stimulation were recorded before (control) and after inhibition of NO formation with Nw-nitro-l-arginine methyl ester (l-NAME). The responses to norepinephrine, tyramine and electrical field stimulation were also recorded in segments, 4 mm in length, from the goat's middle cerebral artery under control conditions and after l-NAME. In vivo, l-NAME (10 goats, 47 mg kg-1 administered i.v.) reduced resting cerebral blood flow by 37+/-2%, increased mean systemic arterial pressure by 24+/-3%, reduced heart rate by 35+/-2%, and decreased cerebrovascular conductance by 52+/-2% (all P<0.01). Norepinephrine (0.3-9 microgram), tyramine (50-500 microgram), and supramaximal electrical sympathetic cervical nerve stimulation (1. 5-6 Hz) decreased cerebrovascular conductance, and these decreases were significantly higher after l-NAME than under control conditions, remaining higher for about 48 h after this treatment. Norepinephrine (10-8-10-3 M), tyramine (10-6-10-3 M) and electrical field stimulation (1.5-6 Hz) contracted isolated cerebral arteries, and the maximal contraction, but not the sensitivity, was significantly higher in the arteries treated than in non-treated with l-NAME (10-4 M). Therefore, the reactivity of cerebral vasculature to exogenous and endogenous norepinephrine may be increased after inhibition of NO synthesis. This increase might be related, at least in part, to changes at postjunctional level in the adrenergic innervation of the vessel wall, and it might contribute to the observed decreases in resting cerebral blood flow after inhibition of NO synthesis.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0006-8993
pubmed:author
pubmed:copyrightInfo
Copyright 1998 Elsevier Science B.V.
pubmed:issnType
Print
pubmed:day
7
pubmed:volume
813
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
381-9
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1998
pubmed:articleTitle
Adrenergic reactivity after inhibition of nitric oxide synthesis in the cerebral circulation of awake goats.
pubmed:affiliation
Departamento de Fisiología, Facultad de Medicina, Universidad Autónoma, Arzobispo Morcillo 4, 28029, Madrid, Spain. godofredo.dieguez@uam.es
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't