| Metabolism of hydroperoxy-phospholipids in human hepatoma HepG2 cells. | |
| | |
MedLine Citation:
|
PMID: 8978487 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
|
Two enzymatic mechanisms have been proposed for the metabolism of hydroperoxy-phospholipids: i) the combined action of phospholipase A2 and glutathione peroxidase, and/or ii) direct enzymatic reduction. The latter reaction may be catalyzed by selenium-dependent phospholipid hydroperoxide glutathione peroxidase and/or by glutathione S-transferase alpha. To study the pathway of this reaction, we used human hepatoma HepG2 cells into which was incorporated labeled, hydroperoxy-phospholipids. The major product of incorporated l-palmitoyl-2-(13-hydroperoxy-cis-9, trans-11-octadecadienoyl)-L-3-phosphatidylcholine was the corresponding hydroxy-phospholipid with no hydroxy- or hydroperoxy-fatty acids. The contributions to reduction of hydroperoxy-phospholipids in HepG2 cells from glutathione S-transferase Al and phospholipid hydroperoxide glutathione peroxidase were calculated to be 0.5% and 99.5%, respectively. Increasing selenium in the cell culture medium led to increases in selenium-dependent phospholipid hydroperoxide glutathione peroxidase activity but not in glutathione S-transferase alpha. This increase in the selenium-dependent enzyme was paralleled by a concomitant increase in the extent of reduction of the incorporated hydroperoxy-phospholipid. We conclude that the main metabolic fate of hydroperoxy-phospholipids in HepG2 cells is by direct reduction to hydroxy-phospholipids by phospholipid hydroperoxide glutathione peroxidase but also by glutathione S-transferase alpha, and that phospholipase A2/selenium-dependent glutathione peroxidase does not play a significant role in the reduction. |
| | |
Authors:
|
Y Bao; G Williamson |
Related Documents
:
|
8612657 - Kinetics of radioiodinated species in subcellular fractions from rat hearts following a... 8439767 - Effects of lysophospholipids and diacylglycerols on the transfer of arachidonic acid to... 4752217 - Membrane fatty acids associated with the electrical response in visual excitation. 11772407 - Pre-steady-state phosphorylation and dephosphorylation of detergent-purified plasma-mem... 15462257 - Synthetic organic food colouring agents and their degraded products: effects on human a... 17267967 - Smaragdicoccus niigatensis gen. nov., sp. nov., a novel member of the suborder coryneba... |
Publication Detail:
|
Type: Journal Article; Research Support, Non-U.S. Gov't |
Journal Detail:
|
Title: Journal of lipid research Volume: 37 ISSN: 0022-2275 ISO Abbreviation: J. Lipid Res. Publication Date: 1996 Nov |
Date Detail:
|
Created Date: 1997-03-25 Completed Date: 1997-03-25 Revised Date: 2007-11-15 |
Medline Journal Info:
|
Nlm Unique ID: 0376606 Medline TA: J Lipid Res Country: UNITED STATES |
Other Details:
|
Languages: eng Pagination: 2351-60 Citation Subset: IM |
Affiliation:
|
Department of Biochemistry, Institute of Food Research, Norwich Laboratory, Norwich Research Park, Colney, United Kingdom. |
Export Citation:
|
APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
|
Carcinoma, Hepatocellular
/
metabolism* Chromatography, High Pressure Liquid Glutathione Peroxidase / metabolism Glutathione Transferase / metabolism Humans Lipid Peroxides / metabolism* Liver Neoplasms / metabolism* Phospholipases A / metabolism Phospholipases A2 Tumor Cells, Cultured |
| Chemical | |
Reg. No./Substance:
|
0/Lipid Peroxides; EC 1.11.1.9/Glutathione Peroxidase; EC 2.5.1.18/Glutathione Transferase; EC 3.1.1.-/Phospholipases A; EC 3.1.1.4/Phospholipases A2 |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
Previous Document: Characterization of the murine phosphatidylethanolamine N-methyltransferase-2 gene.
Next Document: Formation of oxysterols during oxidation of low density lipoprotein by peroxynitrite, myoglobin, and...