Linked Life Data

17934344

Source:http://linkedlifedata.com/resource/pubmed/id/17934344

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
2007-10-15
pubmed:abstractText
Several studies have demonstrated that ischemic preconditioning increases superoxide dismutase activity, but it is unclear how ischemic preconditioning affects events downstream of hydrogen peroxide production during subsequent severe ischemia and reperfusion in the hippocampus. To answer this question, we investigated whether ischemic preconditioning in the hippocampal CA1 region increases the activities of antioxidant enzymes glutathione peroxidase and catalase, resulting in a decrease in the level of hydroxyl radicals during subsequent severe ischemia-reperfusion. Transient forebrain ischemia was induced by four-vessel occlusion in rats. Ischemic preconditioning for 3 min or a sham operation was performed and a 15-min severe ischemia was induced three days later. Ischemic preconditioning preserved the CA1 hippocampal neurons following severe ischemia. The concentration of 2,3-dihydroxybenzoic acid, an indicator of hydroxyl radical, was measured using in vivo microdialysis technique combined with HPLC. The ischemia-induced increase in the ratio of 2,3-dihydroxybenzoic acid concentration relative to baseline did not differ significantly between preconditioned and control groups. On the other hand, activities of the antioxidant enzymes glutathione peroxidase-1 and catalase were significantly increased at 3 days after ischemic preconditioning in the hippocampus. Our results suggest that, in preconditioned rats, while hydrogen peroxide is generated from severe ischemia, the activity of catalase and glutathione peroxidase-1 is correspondingly increased to eliminate the excessive hydrogen peroxide. However, our results show that the enhanced activity of these antioxidant enzymes in preconditioned rats is not sufficient to decrease hydroxyl radical levels during subsequent severe ischemia-reperfusion.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
1226-3613
pubmed:author
pubmed:issnType
Print
pubmed:day
31
pubmed:volume
39
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
556-63
pubmed:meshHeading
pubmed:year
2007
pubmed:articleTitle
Ischemic preconditioning in the rat hippocampus increases antioxidant activities but does not affect the level of hydroxyl radicals during subsequent severe ischemia.
pubmed:affiliation
Department of Pharmacology, College of Medicine, The Catholic University of Korea, Seoul 137-701, Korea.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't