Vascular reactivity and metabolism of the reactive forms of oxygen and nitrogen: effects of low doses of radiation

Endothelium-dependent and endothelium-independent vascular reactions of relaxation, the rate of reactive oxygen species (superoxide and hydroxyl) generation, the content of stable nitric oxide (NO) metabolites (nitrite, nitrate and nitrosothiols), the pools of lipid peroxidation products (eicosanoids LTC 4 and TxB 2 , dienic conjugates and malonic dialdehyde), H 2 O 2 , uric acid and urea were studied in aorta preparations of BALB/c 9 months-old mice: group I – control; group II – exposed to chronic external low doses γ -irradiation (equivalent dose of 96.9 μSv·h –1 ) mice (cumulative dose of 0.43 Sv). The results obtained showed disturbances in the studied reactions and change of the reactive forms of oxygen and nitrogen following an effect of low doses of radiation. The latter induce significant changes in the pools of NO stable metabolites, which can cause disturbances in the NO-dependent physiological functions of heart and aorta. A significant decrease in the levels of nitrite and S-nitrosothiols can...