The decrease in antioxidant potential in human brain tumours

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.

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.