Linked Life Data

10832063

Source:http://linkedlifedata.com/resource/pubmed/id/10832063

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
7
pubmed:dateCreated
2000-7-18
pubmed:abstractText
Manganese porphyrin complexes serve to catalytically scavenge superoxide, hydrogen peroxide, and peroxynitrite. Herein, reactions of manganese 5,10,15,20-tetrakis(N-ethylpyridinium-2-yl)porphyrin (MnTE-2-PyP(5+)) with lipids and lipid hydroperoxides (LOOH) are examined. In linoleic acid and human low-density lipoprotein (LDL), MnTE-2-PyP(5+) promotes oxidative reactions when biological reductants are not present. By redox cycling between Mn(+3) and Mn(+4) forms, MnTE-2-PyP(5+) initiates lipid peroxidation via decomposition of 13(S)hydroperoxyoctadecadienoic acid [13(S)HPODE], with a second-order rate constant of 8.9 x 10(3) M(-1)s(-1)and k(cat) = 0.32 s(-1). Studies of LDL oxidation demonstrate that: (i) MnTE-2-PyP(5+) can directly oxidize LDL, (ii) MnTE-2-PyP(5+) does not inhibit Cu-induced LDL oxidation, and (iii) MnTE-2-PyP(5+) plus a reductant partially inhibit lipid peroxidation. MnTE-2-PyP(5+) (1-5 microM) also significantly inhibits FeCl(3) plus ascorbate-induced lipid peroxidation of rat brain homogenate. In summary, MnTE-2-PyP(5+) initiates membrane lipid and lipoprotein oxidation in the absence of biological reductants, while MnTE-2-PyP(5+) inhibits lipid oxidation reactions initiated by other oxidants when reductants are present. It is proposed that, as the Mn(+3) resting redox state of MnTE-2-PyP(5+) becomes oxidized to the Mn(+4) redox state, LOOH is decomposed to byproducts that propagate lipid oxidation reactions. When the manganese of MnTE-2-PyP(5+) is reduced to the +2 state by biological reductants, antioxidant reactions of the metalloporphyrin are favored.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0891-5849
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
28
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1017-29
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed-meshheading:10832063-Animals, pubmed-meshheading:10832063-Brain Chemistry, pubmed-meshheading:10832063-Catalysis, pubmed-meshheading:10832063-Chromatography, Thin Layer, pubmed-meshheading:10832063-Free Radical Scavengers, pubmed-meshheading:10832063-Humans, pubmed-meshheading:10832063-Linoleic Acid, pubmed-meshheading:10832063-Linoleic Acids, pubmed-meshheading:10832063-Lipid Peroxidation, pubmed-meshheading:10832063-Lipid Peroxides, pubmed-meshheading:10832063-Lipids, pubmed-meshheading:10832063-Lipoproteins, pubmed-meshheading:10832063-Lipoproteins, LDL, pubmed-meshheading:10832063-Male, pubmed-meshheading:10832063-Manganese, pubmed-meshheading:10832063-Mass Spectrometry, pubmed-meshheading:10832063-Metalloporphyrins, pubmed-meshheading:10832063-Oxidation-Reduction, pubmed-meshheading:10832063-Rats, pubmed-meshheading:10832063-Rats, Sprague-Dawley
pubmed:year
2000
pubmed:articleTitle
Manganese-porphyrin reactions with lipids and lipoproteins.
pubmed:affiliation
Department of Anesthesiology, Biochemistry and Molecular Genetics, Pharmacology and Toxicology, and The Center for Free Radical Biology, University of Alabama at Birmingham, Birmingham, AL 35233, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't