Elevation of antioxidant potency in mice brain by low-dose X-ray irradiation and its effect on Fe-NTA-induced brain damage.
The increase in lipid peroxide levels in mice brain following Fe3+ administration was about 50% of that when 1-methyl-4-phenyl 1,2,3,6-tetrahydropyridine (MPTP) was administered. This may be due to excessive oxidation by Fe3+, and was supported by the decrease in activities of antioxidant enzymes, such as superoxide dismutase (SOD), catalase and glutathione peroxidase (GPX), Na+,K(+)-ATPase activity and membrane fluidity after Fe3+ administration. Relatively low-dose X-ray irradiation (0.5 Gy) inhibited lipid peroxidation associated with Fe3+ administration and restored the decreased activities of the above antioxidant enzymes and Na+,K(+)-ATPase, and membrane fluidity to the levels in the non-Fe(3+)-administered group. In the purine metabolism system, uric acid decreased after Fe3+ administration, which may be due to transient impairment of the system for production of uric acid from xanthine by excessive oxidation by Fe3+. However, 0.5 Gy irradiation inhibited this decrease in uric acid, increasing its level to that in the non Fe(3+)-administrated group. This may be due to factors such as rapid recovery of the activities of the above antioxidant enzymes and Na+,K(+)-ATPase, and membrane fluidity after 0.5 Gy irradiation. In addition, since no changes were observed in xanthine and uric acid, increased inosine and hypoxanthine may have advanced to a salvage pathway leading to not xanthine but inosine 5'-monophosphate (IMP).
Yamaoka
Kiyonori
K
Medical Radioscience, Okayama University Medical School, Okayama 700-8558, Japan.
Mori
Shuji
S
Nomura
Takaharu
T
Taguchi
Takehito
T
Ito
Takehiko
T
Hanamoto
Katsumi
K
Kojima
Shuji
S
D000818:Animals; D000975:Antioxidants / Q000032:analysis / Q000378:metabolism*; D001921:Brain / Q000187:drug effects* / Q000378:metabolism / Q000528:radiation effects*; D001925:Brain Damage, Chronic / Q000139:chemically induced; D002374:Catalase / Q000032:analysis / Q000378:metabolism; D004351:Drug Resistance / Q000528:radiation effects; D004357:Drug Synergism; D004789:Enzyme Activation / Q000187:drug effects / Q000528:radiation effects; D005290:Ferric Compounds / Q000633:toxicity*; D005979:Glutathione Peroxidase / Q000032:analysis / Q000378:metabolism; D008054:Lipid Peroxides / Q000032:analysis / Q000378:metabolism; D008297:Male; D008560:Membrane Fluidity / Q000187:drug effects / Q000528:radiation effects; D051379:Mice; D008810:Mice, Inbred C57BL; D009474:Neurons / Q000187:drug effects / Q000378:metabolism / Q000528:radiation effects; D009571:Nitrilotriacetic Acid / Q000031:analogs & derivatives* / Q000633:toxicity*; D012016:Reference Values; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D000254:Sodium-Potassium-Exchanging ATPase / Q000032:analysis / Q000378:metabolism; D013482:Superoxide Dismutase / Q000032:analysis / Q000378:metabolism; D014916:Whole-Body Irradiation
D000975:Antioxidants; D005290:Ferric Compounds; D008054:Lipid Peroxides; D002374:Catalase; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; D000254:Sodium-Potassium-Exchanging ATPase; D009571:Nitrilotriacetic Acid; C020326:ferric nitrilotriacetate