Linked Life Data

8026802

Source:http://linkedlifedata.com/resource/pubmed/id/8026802

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
1994-8-5
pubmed:abstractText
The role of free-radical-induced lipid peroxidation (LPO) in relation to lens opacity is investigated using Fourier transform infrared spectroscopy. Phospholipids extracted from nuclear and cortical regions of the rabbit lens membranes are subjected to oxidative-damage induced by hydrogen peroxide and Fe2+/Fe3+ cations. Vibrational data suggest a homolytic decomposition of the unsaturated membrane hydrocarbon chains at cis-double bonds, as well as structural modifications at the carbonyl and phosphate-oxygen sites of the fiber cell membranes upon metal oxidation. This is also evident from a substantial induction of the carbonyl groups and a significant dephosphorylation of the phosphate groups in lens phospholipids. These covalent modifications and/or alterations of the carbonyl and phosphate groups, and specificity of certain vibrational modes only to iron oxidation, may serve as a diagnostic probe of the metal-catalyzed LPO in lens membranes. Despite covalent modifications of the hydrophilic part of the lens membranes, hydrocarbon chain region remains largely intact at physiological concentrations of hydrogen peroxide. However, at elevated concentrations of hydrogen peroxide, a substantial breakdown of the acyl chains occurs. Striking similarities observed between the spectral features of the oxidized rabbit lens phospholipids and those of the cataractous human lenses suggest that the mechanism and pathways of lipid oxidation in model animal membranes and in human lenses are similar. Differences in the nuclear or cortical regions are also evident upon metal oxidation. Nuclear lipids experience increased effects of the metal oxidation compared to cortical lipids. Both the nuclear or the cortical lipids indicate effective penetration of the bilayer water creating segregated membrane domains, possibly through breakdown of headgroup-specific lipid-water interactions. This could effectively alter the lens membrane permeability and fluidity, rendering it susceptible to a host of toxic oxidants present in the eye. These findings also demonstrate that LPO can lead to acyl chain degradation that may effectively derange the lens membrane function, which could be a contributing factor in cataractogenesis.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0891-5849
pubmed:author
pubmed:issnType
Print
pubmed:volume
16
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
591-601
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1994
pubmed:articleTitle
Spectral characterization of lipid peroxidation in rabbit lens membranes induced by hydrogen peroxide in the presence of Fe2+/Fe3+ cations: a site-specific catalyzed oxidation.
pubmed:affiliation
Department of Ophthalmology and Visual Sciences, University of Louisville School of Medicine, Kentucky Lions Eye Research Institute 40292.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't