Study of the oxidative stress in a rat model of chronic brain hypoperfusion.
A multiple analysis of the cerebral oxidative stress was performed on a physiological model of dementia accomplished by three-vessel occlusion in aged rats. The forward rate constant of creatine kinase, k(for), was studied by saturation transfer (31)P magnetic resonance spectroscopy in adult and aged rat brain during chronic hypoperfusion. In addition, free radicals in aging rat brain homogenates before and/or after occlusion were investigated by spin-trapping electron paramagnetic resonance spectroscopy (EPR). Finally, biochemical measurements of oxidative phosphorylation parameters in the above physiological model were performed. The significant reduction of k(for) in rat brain compared to controls 2 and 10 weeks after occlusion indicates a disorder in brain energy metabolism. This result is consistent with the decrease of the coefficient of oxidative phosphorylation (ADP:O), and the oxidative phosphorylation rate measured in vitro on brain mitochondria. The EPR study showed a significant increase of the ascorbyl free radical concentration in this animal model. Application of alpha-phenyl-N-tert-butylnitrone (PBN) and 5,5-dimethyl-1-pyrroline N-oxide (DMPO) spin traps revealed formation of highly reactive hydroxyl radical (.OH) trapped in DMSO as the .CH(3) adduct. It was concluded that the ascorbate as a major antioxidant in brain seems to be useful in monitoring chronic cerebral hypoperfusion.
Kasparová
Svatava
S
NMR Laboratory, Faculty of Chemical and Food Technology, Slovak University of Technology, Radlinského 9, SK-812 37 Bratislava, Slovakia. kasparov@cvt.stuba.sk
Brezová
Vlasta
V
Valko
Marián
M
Horecký
Jaromír
J
Mlynárik
Vladimír
V
Liptaj
Tibor
T
Vancová
Ol'ga
O
Ulicná
Ol'ga
O
Dobrota
Dusan
D
D000818:Animals; D001205:Ascorbic Acid / Q000378:metabolism; D001921:Brain / Q000378:metabolism* / Q000503:physiopathology; D002545:Brain Ischemia / Q000378:metabolism* / Q000503:physiopathology; D002908:Chronic Disease; D003402:Creatine Kinase / Q000378:metabolism; D003497:Cyclic N-Oxides / Q000494:pharmacology; D003704:Dementia / Q000378:metabolism* / Q000503:physiopathology; D004195:Disease Models, Animal; D004734:Energy Metabolism / Q000502:physiology*; D005609:Free Radicals / Q000378:metabolism; D017665:Hydroxyl Radical / Q000378:metabolism; D008297:Male; D008928:Mitochondria / Q000378:metabolism; D008968:Molecular Conformation; D009589:Nitrogen Oxides / Q000494:pharmacology; D010085:Oxidative Phosphorylation; D018384:Oxidative Stress / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar; D019097:Spin Trapping
D003497:Cyclic N-Oxides; D005609:Free Radicals; D009589:Nitrogen Oxides; D017665:Hydroxyl Radical; C029217:phenyl-N-tert-butylnitrone; C017245:5,5-dimethyl-1-pyrroline-1-oxide; D003402:Creatine Kinase; D001205:Ascorbic Acid