title: The decrease in antioxidant potential in human brain tumours.
abstract: The objective of our research was to estimate the activity of superoxide dismutase (SOD-1), glutathione peroxidase (GSH-Px) and glutathione reductase (GSSG-R), as well as the concentrations of free oxygen radicals "sweepers" (GSH, Vit.C) and the concentrations of the substances reacting with thiobarbituric acid in brain tumours with II, III and IV level of biological malignancy. The research was conducted on 61 samples obtained from the patients operated in the Department of Neurosurgery of the Medical Academy of Białystok between the years 1996 and 2000. The obtained values of the above enzyme activities and of the concentrations of the examined substances in brain tumours were compared to the adequate values determined in 10 samples of histopathologically unchanged nerve tissue.
  
  
  RESULTS
  the increase of all enzymes activities in brain tumours is statistically significant (p < 0.05) as compared to the adequate activity level in normal nerve tissue. The significant decrease (p < 0.05) of the GSH and ascorbate concentration and the significant increase (p < 0.05) of the level of the thiobarbituric acid--reactive substances in the examined brain tumours was found in comparison to the adequate concentration of the above substances in normal nerve tissue.
authors.affiliation: Department of Neurosurgery, Medical Academy of Białystok, Białystok, Poland.
authors.forename: Henryk
authors.initials: H
authors.lastname: Dudek
authors.forename: Ryszard
authors.initials: R
authors.lastname: Farbiszewski
authors.forename: Tadeusz
authors.initials: T
authors.lastname: Michno
authors.forename: Artur
authors.initials: A
authors.lastname: Witek
authors.forename: Andrzej
authors.initials: A
authors.lastname: Kozłowski
authors.forename: Maria
authors.initials: M
authors.lastname: Rydzewska
mesh_terms: D000975:Antioxidants / Q000032:analysis / Q000378:metabolism; D001254:Astrocytoma / Q000201:enzymology / Q000473:pathology / Q000601:surgery; D001707:Biopsy, Needle; D001923:Brain Chemistry; D001932:Brain Neoplasms / Q000201:enzymology* / Q000473:pathology / Q000601:surgery; D002648:Child; D046508:Culture Techniques; D005260:Female; D005909:Glioblastoma / Q000201:enzymology / Q000473:pathology / Q000601:surgery; D005979:Glutathione Peroxidase / Q000378:metabolism*; D005980:Glutathione Reductase / Q000378:metabolism*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011336:Probability; D011379:Prognosis; D017382:Reactive Oxygen Species / Q000378:metabolism*; D012494:Sampling Studies; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D013482:Superoxide Dismutase / Q000378:metabolism*
chemical_list: D000975:Antioxidants; D017382:Reactive Oxygen Species; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; D005980:Glutathione Reductase