[Acute hypoxia induce free radicals generation in rat's cortex and hippocampus].
Anesthetized rats were ventilated artificially to 10.5%-11.0% O2 in N2 (equivalent to altitude about 5 000 m). PBN (alpha-phenyl-ter-butylnitrone) was injected intravenously 5 min before hypoxia. The experiment results showed that the ESR (electron spin resonance) signal intensity of PBN-spin adduct in cortex and hippocampus both increased significantly during hypoxia (15 min) as compared with normoxia group (n = 5, P < 0.01). In the third group of rats injected with MPEG-SOD (monomethoxy-polyethylene glycol-superoxide dismutase) intravenously 20 min before hypoxia, the ESR signal intensity of PBN-spin adduct in cortex and hippocampus did not decrease significantly under hypoxia for 15 min (compared with hypoxia group, n = 5, P > 0.05). This may be due to the fact that MPEG-SOD could not pass the blood-brain barrier owing to its large molecular weight. The enzyme activity of SOD (superoxide dismutase. EC 1.15.1.1), GSH-Px (Glutathione peroxidase, EC 1.11.1.9) and content of MDA (malondialdehyde) was also determined. The results showed that the hypoxia had no effect on the SOD, GSH-Px activity and MDA content (n = 7 or n = 8, P > 0.05). The above results suggested that ventilation to 10.5%-11.0% O2 in N2 15 min induced free radical generation in rat's cortex and hippocampus, but this generation was not due to decrease of SOD, GSH-Px activity in cortex and hippocampus.
Wang
Q H
QH
Shanghai Instiute of Physiology, Chinese Academy of Sciences.
Han
Z Y
ZY
Chen
M
M
Wen
P
P
D000818:Animals; D002540:Cerebral Cortex / Q000378:metabolism*; D003497:Cyclic N-Oxides; D004578:Electron Spin Resonance Spectroscopy; D005609:Free Radicals / Q000378:metabolism; D006624:Hippocampus / Q000378:metabolism*; D000860:Hypoxia / Q000378:metabolism*; D008297:Male; D008315:Malondialdehyde / Q000378:metabolism; D009589:Nitrogen Oxides; D051381:Rats; D017207:Rats, Sprague-Dawley; D013113:Spin Labels; D013482:Superoxide Dismutase / Q000378:metabolism
D003497:Cyclic N-Oxides; D005609:Free Radicals; D009589:Nitrogen Oxides; D013113:Spin Labels; C029217:phenyl-N-tert-butylnitrone; D008315:Malondialdehyde; D013482:Superoxide Dismutase