Switch to
| Predicate | Object |
|---|---|
| rdf:type | |
| lifeskim:mentions | |
| pubmed:issue |
9
|
| pubmed:dateCreated |
1993-4-22
|
| pubmed:abstractText |
The variation of the selenium status of leukocytes was used as a tool to investigate the influence of selenium-containing glutathione peroxidases on the formation of 5-lipoxygenase metabolites in vitro and ex vivo. Selenium-deficient rat basophilic leukemia cells had < 1% of control glutathione peroxidase activity and 35% of control phospholipid hydroperoxide-glutathione peroxidase activity. Upon stimulation, these cells released an 8-fold amount of lipoxygenase metabolites compared to controls. No (5S)-hydroperoxyeicosatetraenoic acid was detectable in whole cells; however, it was found in homogenates of selenium-deficient cells. Addition of 0.25 microgram/ml selenium to selenium-deficient cells restored control phospholipid hydroperoxide-glutathione peroxidase activity within 8 h, whereas glutathione peroxidase activity needed 7 days. 12 h after resupplementation, selenium-deficient cells had 3% glutathione peroxidase and 100% phospholipid hydroperoxide-glutathione peroxidase activity compared to controls. Resupplemented cells released control amounts of 5-lipoxygenase metabolites, indicating that restoration of phospholipid hydroperoxide-glutathione peroxidase activity is associated with a selenium-adequate leukotriene metabolism. Leukocytes that were isolated from selenium-deficient rats released a 7-fold amount of total lipoxygenase metabolites compared to cells from control animals. By injecting normally fed rats with 500 micrograms/kg selenium as Na2SeO3, leukocyte phospholipid hydroperoxide-glutathione peroxidase activity was raised 8-fold within 114 h compared to controls. Leukocytes from these animals produced significantly less lipoxygenase metabolites than controls. These findings indicate that phospholipid hydroperoxide-glutathione peroxidase activity is primarily responsible for the reduction of 5-hydroperoxyeicosate-traenoic acid and therefore governs the actual activity of leukocyte 5-lipoxygenase via regulating the tone of endogenous hydroperoxides.
|
| pubmed:language |
eng
|
| pubmed:journal | |
| pubmed:citationSubset |
IM
|
| pubmed:chemical | |
| pubmed:status |
MEDLINE
|
| pubmed:month |
Mar
|
| pubmed:issn |
0021-9258
|
| pubmed:author | |
| pubmed:issnType |
Print
|
| pubmed:day |
25
|
| pubmed:volume |
268
|
| pubmed:owner |
NLM
|
| pubmed:authorsComplete |
Y
|
| pubmed:pagination |
6288-92
|
| pubmed:dateRevised |
2003-11-14
|
| pubmed:meshHeading |
pubmed-meshheading:8454601-Animals,
pubmed-meshheading:8454601-Arachidonate 5-Lipoxygenase,
pubmed-meshheading:8454601-Enzyme Activation,
pubmed-meshheading:8454601-Glutathione Peroxidase,
pubmed-meshheading:8454601-Kinetics,
pubmed-meshheading:8454601-Leukocytes,
pubmed-meshheading:8454601-Male,
pubmed-meshheading:8454601-Peroxides,
pubmed-meshheading:8454601-Rats,
pubmed-meshheading:8454601-Rats, Wistar,
pubmed-meshheading:8454601-Selenium,
pubmed-meshheading:8454601-Tumor Cells, Cultured
|
| pubmed:year |
1993
|
| pubmed:articleTitle |
Selenoenzymes regulate the activity of leukocyte 5-lipoxygenase via the peroxide tone.
|
| pubmed:affiliation |
Faculty of Biology, University of Konstanz, Germany.
|
| pubmed:publicationType |
Journal Article
|