Lack of correlation between TBARS production and PUFA degradation during incubation of membrane erythrocytes in an OH. (Fe2+/H2O2) generator system.
We investigated the effects of an OH. (Fe2+/H2O2) generator system on erythrocyte membrane, particularly the time-course of lipid peroxidation as estimated by measurement of conjugated dienes, thiobarbituric reactive substances (TBARS), lipofuscin-like pigments, and alpha-tocopherol. Polyunsaturated fatty acids (PUFAs), especially arachidonic acid (20:4 omega 6) and docosahexenoic acid (22:6 omega 3), were also measured. Erythrocyte membranes were suspended in phosphate buffer containing Fe2+ (200 microM) and H2O2 (1.42 mM), and incubated in a shaking water bath at 37 degrees C. Initially, there was an increase in TBARS and lipofuscin-like pigments, two well-known end products of PUFA oxidative degradation, whereas PUFAs remained unchanged (incubation time: 1 h). After two or more hours of incubation, marked lipid peroxidation was noted, with the appearance of conjugated dienes and a decrease of PUFAs, indicating that lipid peroxidation had occurred after a lag phase during which TBARS were not produced from PUFAs. This suggests that another OH. target was involved.
Tallineau
C
C
Institut des Xénobiotiques et Laboratoire de Biochimie, Faculté de Médecine et de Pharmacie, Poitiers, France.
Barrier
L
L
Fauconneau
B
B
Guettier
A
A
Piriou
A
A
D016718:Arachidonic Acid / Q000097:blood; D004281:Docosahexaenoic Acids / Q000097:blood; D004910:Erythrocyte Membrane / Q000378:metabolism*; D005231:Fatty Acids, Unsaturated / Q000097:blood*; D006801:Humans; D006861:Hydrogen Peroxide; D017665:Hydroxyl Radical / Q000494:pharmacology*; D007501:Iron; D007700:Kinetics; D008062:Lipofuscin / Q000097:blood; D017392:Thiobarbituric Acid Reactive Substances / Q000378:metabolism*; D014810:Vitamin E / Q000097:blood
D005231:Fatty Acids, Unsaturated; D008062:Lipofuscin; D017392:Thiobarbituric Acid Reactive Substances; D014810:Vitamin E; D004281:Docosahexaenoic Acids; D016718:Arachidonic Acid; D017665:Hydroxyl Radical; D006861:Hydrogen Peroxide; D007501:Iron