Linked Life Data

10747003

Source:http://linkedlifedata.com/resource/pubmed/id/10747003

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
2000-4-19
pubmed:databankReference
pubmed:abstractText
The goal of this study was to determine whether hypoxia alters expression of endothelial nitric oxide synthase (eNOS) in the systemic circulation. Rats breathed either air or 10% oxygen for 12 hours, 48 hours, or 7 days. Thoracic aortas were excised and either mounted in organ bath myographs or frozen in liquid nitrogen for later extraction of protein and RNA. eNOS protein (Western blotting) was decreased (20% of normoxic control) after 12 hours, 48 hours, and 7 days of hypoxia. eNOS mRNA (ribonuclease protection assay) was similarly reduced. Acetylcholine (10(-4) mol/L) reversed phenylephrine (10(-5) mol/L) preconstriction by 53.3+/-5.6% in aortic rings from normoxic rats and 26.1+/-4.8% in rings from rats exposed to hypoxia for 48 hours (P<0.05), with comparable impairment of relaxation by the calcium ionophore A23187 (10(-5) mol/L). Responses to diethylamine nitric oxide and 8-bromo-cGMP were unaffected. Aortic cGMP levels after incubation with acetylcholine (10(-6) mol/L) averaged 14.0+/-1.8 fmol/mg in rings from normoxic rats compared with 8.7+/-1.0 fmol/mg in rings from hypoxic rats (P<0. 05). Similarly, nitrate concentration (by capillary electrophoresis) in the media in which the rings were incubated was reduced in the hypoxic group (5.6+/-0.23 micromol/L for hypoxic rats and 7.8+/-0.7 micromol/L for normoxic rats). Impaired endothelial NO release may handicap the vascular responses that defend vital organ function during hypoxia.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0009-7330
pubmed:author
pubmed:issnType
Print
pubmed:day
31
pubmed:volume
86
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
671-5
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2000
pubmed:articleTitle
Downregulation of endothelial nitric oxide synthase in rat aorta after prolonged hypoxia in vivo.
pubmed:affiliation
Meakins-Christie Laboratories, McGill University, Montréal, Québec, Canada.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't