[Antioxidant system of platelets in patients with ovary cancer]

The activities of lipid peroxidation and of platelets' antioxidant protection were investigated in 30 healthy women and in 44 patients with primarily diagnosed different-stage ovary cancer (OC). An essentially higher activity of superoxide dimutase (SOD, by 2.5 times) and of catalase (by 1.5 times) was detected in platelets of OC patients versus the norm. A simultaneous increase of malonic dialdehyde (MDA) by 2.5 times denotes a free-radical activation. There was also an insignificant growth of the glutathione level, whereas the activity of glutathione-S-transferase (GST) did not virtually change. A comparative analysis of the biochemical indices of patients with different stages of the disease revealed valuable distinctions related with a higher activity of SOD and catalase in stages 3-4 versus the initial stages. Notworthility, the MDA level was decreasing. Minor changes in the system of glutathione are not obviously decisive in impairing the regulatory mechanism of antioxidant protection in platelets unlike in malignant cells. The results provide a solid basis for assuming that the impact made by deranged regulations of free radicals on the platelet chain in the hemostasis system causes changes in the blood rheological properties entailing a higher aggregation of platelets, thus, triggering the onset of platelet-embolic complications in the discussed patient category. The impaired regulation mechanism of antioxidant protection in platelets is a major manifestation of the oxidant stress evolving due to a growing tumor; the mechanism is important for evaluating the structural-and-functional platelets' condition.