Анотація:
Aim: To examine the relationship between metabolic features of purine nucleotides and antioxidant system depending on the age of patients with colorectal cancer. Materials and Methods: The activity of adenosine deaminase, xanthine oxidase, glutathione peroxidase, superoxide dismutase and glucose-6-phosphate dehydrogenase, the NOx concentration and the oxidative modification of proteins were determined spectrophotometricaly in 50 apparently healthy people and 26 patients with colorectal cancer stage III–IV, aged 40 to 79 years. Results: Increase of pro-oxidant system of erythrocytes with the age against decrease in level of antioxidant protection in both healthy individuals and colorectal cancer patients was determined. A significant increase of products of oxidative proteins modification in erythrocytes with ageing was shown. Statistically significant correlation between enzymatic and non enzymatic markers pro-oxidant system and the activity of antioxidant defense enzymes in erythrocytes of patient with colorectal cancer was determined. Conclusion: Obtained results have demonstrated the imbalance in the antioxidant system of erythrocytes in colorectal cancer patients that improve the survival of cancer cells that is more distinctly manifested in ageing. Key Words: age, colorectal cancer, erythrocyte, nucleotides, antioxidants, oxidative stress.