[Oxidative stress in platelets at an oncopathology]

To determine the biochemical disorders in the blood coagulation mechanism associated with oxidative stress parameters of the antioxidant status were examined in platelets of 57 colorectal cancer patients, (including 21 patients before and after surgery), and 40 healthy individuals. We determined the total content of nitric oxide (NOx), levels of superoxide dismutase (Cu/ZnSOD), glutathione and malondialdehyde (MDA). Before treatment, we observed the changes in the antioxidant defense system of platelets, which did not depend on the prevalence of malignancy: elevated levels of SOD by 16% (p<0.05), reduced glutathione and MDA in 5.2 and 1.7 times, respectively. NOx levels did not differ from the norm. Significant shifts were found in the postoperative period: they consisted of the increase in the generation of NOx both on the third, and on the 10-th day after surgery. These changes reflect apparently platelet response to the inflammatory process associated with the surgical trauma and confirm the role of NOx as a mediator of inflammation. The content of SOD after surgery was significantly reduced, but return to a baseline on the 10-th day. Despite the significant increase in the number of platelets, no correlations of the studied parameters and their aggregation ability were found.The findings suggest that metabolic disorders in vascular-platelet hemostasis are associated with oxidative stress, which provides a basis for further study of the relationship of cancer to thrombosis.