SUMMARY
Introduction. The simultaneous effect of several ulcerogenic factors, different due to their mechanism of action on the mucous membranes of the digestive organs needs deep elucidation. The studies were focused on the combined effect of the low intensity X-ray irradiation and cyclooxygenase blockage. It is important to evaluate the antioxidant effect of vitamin E under the conditions of simultaneous effect of different pro-inflammatory factors, acting on the nitroso-oxidative processes.The aim of the study – to investigate the effect of vitamin E on nitroso-oxidative processes in the mucous membranes of the digestive organs under the action of the low intensity X-ray irradiation and COX blockage.Research Methods. In the homogenates of the mucous membranes of stomach, small and large intestine in rats (n=64) the activity of NO-synthase, arginase, myeloperoxidase, superoxide dismutase, catalase, TBA-active products,nitrite-anioncontent and sum of nitrites and nitrates were determined.Results and Discussion. It was established that the effect of vitamin E on the background of the low intensity X-ray irradiation resulted in the decrease of iNOSactivity level (?<0.05) and nitrite-anion content (?<0.05) and increase of catalase and MPO activity in the mucous membranes of the digestive organs compared to indices obtained under the conditions of X-ray irradiation. Blockage of COX activity by indometacin on the background of the introduction of vitamin E and simultaneous effect of the low intensity X-ray irradiation revealed the peculiarities of antioxidant action of vitamin E in the mucous membranes of the digestive organs. Conclusions.Under the conditions of COX blockage on the background of the low intensity X-ray irradiation the level of lipid peroxidation processes increased, iNOSand ?NOS activity decreased compared to indices under the independent effect of irradiation, whereas compared to data under the effect of indometacin lipid peroxidation processes and iNOS activity decreased. Vitamin E exerts antioxidant effect under the conditions of ulcerative action of indometacin on the background of the X-ray irradiation.