Linked Life Data

14744923

Source:http://linkedlifedata.com/resource/pubmed/id/14744923

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2004-2-27
pubmed:abstractText
Less nitric oxide (NO)-dependent vasodilation and excess formation of reactive oxygen species could explain poor placenta perfusion in preeclampsia, but the pathways involved are unknown. We tested the hypothesis that reduced NO activity and increased oxidative stress in preeclamptic placenta is related to a low bioavailability of l-arginine. Placental endothelial NO synthase (ecNOS) expression (by immunoperoxidase) and activity (by diaphorase and [(3)H]L-citrulline formation) were comparable in normotensive pregnancy and in preeclampsia, whereas nitrotyrosine staining, a marker of peroxynitrite, was stronger in preeclamptic villi, confirming previously reported data. Oxidative tissue damage was documented in preeclamptic villi by strong 4-hydroxynonenal-lysine staining (by immunoperoxidase), which closely colocalized with nitrotyrosine. Concentration of the NO precursor l-arginine (by HPLC) in umbilical blood and in villous tissue was lower in preeclampsia than in normotensive pregnancy. This was not caused by a defective l-arginine transport, because gene expression of the CAT-1, 4F2hc, and LAT-1 cationic amino acid transporters (by real-time reverse-transcription polymerase chain reaction [RT-PCR]) was normal. Instead, gene expression (by real-time RT-PCR) and protein tissue content (by immunoperoxidase and Western blot) of arginase II-the enzyme that degrades arginine to ornithine-were higher in preeclamptic villi than in normotensive pregnancy. These results provide a biochemical explanation for defective NO activity and increased oxidative stress in preeclamptic placenta. In normal placenta, adequate concentration of l-arginine orients ecNOS toward NO. In preeclampsia, a lower than normal l-arginine concentration caused by arginase II overexpression redirects ecNOS toward peroxynitrite.
pubmed:commentsCorrections
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
1524-4563
pubmed:author
pubmed:issnType
Electronic
pubmed:volume
43
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
614-22
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2004
pubmed:articleTitle
L-arginine depletion in preeclampsia orients nitric oxide synthase toward oxidant species.
pubmed:affiliation
Mario Negri Institute for Pharmacological Research, Via Gavazzeni, 11, 24125 Bergamo, Italy. noris@marionegri.it
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't