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Oxidative damage to proteins and lipids of CNS myelin produced by in vitro generated reactive oxygen species
Author(s) -
Bongarzone E. R.,
Pasquini J. M.,
Soto E. F.
Publication year - 1995
Publication title -
journal of neuroscience research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.72
H-Index - 160
eISSN - 1097-4547
pISSN - 0360-4012
DOI - 10.1002/jnr.490410209
Subject(s) - tbars , reactive oxygen species , oxidative stress , ascorbic acid , chemistry , lipid peroxidation , thiobarbituric acid , biochemistry , myelin , free radical theory of aging , in vitro , polyunsaturated fatty acid , fatty acid , central nervous system , biology , endocrinology , food science
Purified myelin isolated from 70‐day‐old rats was submitted to nonenzymatic peroxidative systems containing 100 μM FeC1 3 .6H 2 O,100 μM ascorbic acid, and 100 μM CuSO 4 .6H 2 O 10 mM H 2 O 2 in order to investigate the extent of damage produced by reactive oxygen species (ROS). Iron and copper catalyzing systems were selected because of the known importance of these metals in producing free radical chain reactions in biological membranes (Halliwell and Gutteridge: “Free Radicals in Biology and Medicine,” Oxford: Clarendon Press, 1989). Our findings, show that (1) although after 1 hour of peroxidation, an important level of thiobarbituric acid‐reactive substances (TBARS) was detected, polyunsaturated fatty acids (20:2; 20:4; 22:4 and 22:6) were markedly affected only after 14 hours of incubation; (2) protein thiol groups were very sensitive to the attack of ROS generated by copper but resistant to iron‐generated ROS; (3) aggregation of myelin proteins produced by peroxidation could be prevented by sulfhydryl (SH)‐reducing agents, and (4) as a consequence of these modifications, compact myelin suffered disruption of its intraperiodic line. In conclusion, our results demonstrate that this unique membrane of the central nervous system (CNS) is highly vulnerable to oxidative stress and that this susceptibility to oxidative damage could be prevented, at least partially, by the use of SH‐protective molecules. © 1995 Wiley‐Liss, Inc.