[Age-related characteristics of contractile vascular reactions and the content of oxygen free radicals and nitric oxide metabolites in BALB/c mice in conditions of alienation zone].

: Peculiarities of changes of the endothelium-dependent and endothelium-independent vascular reactions of relaxation, and the content of oxygen free radicals and stable metabolites of nitric oxide (NO) were studied in the aorta preparations of BALB/c mice of the two age groups (6 and 18 months), which were born and lived in the Chernobyl alienation zone. The results obtained showed no endothelium-dependent reactions of aortal smooth muscles relaxation to acetylcholine and only partially impaired endothelium-independent reactions to sodium nitroprusside in animals of both age groups. There was a significant decrease in the content of high-molecular nitrosothiols (HMNT) in old animals, which may signify a depletion of NO depot in the aorta. A decrease of HMNT levels induced an increase of the shares of anion nitrite and low-molecular nitrosothiols (LMNT) in the total amount of endogenous donors of NO in the aorta of old animals. Exposure of old animals to low doses of radiation resulted in an over 3-fold increase of LMNT. In old mice the levels of oxygen active forms, superoxide and hydroxyl radicals increase, while the level of H2O2 remained unchanged.