FEATURES OF NITRIC OXIDE METABOLISM AND RISK OF DEVELOPING ENDOTHELIAL DYSFUNCTION IN CHILDREN WITH e-NOS GENE 4a/4b POLYMORPHISM UNDER LONG-TERM ENTERING 137Cs TO BODY.

OBJECTIVE: To determine the features of the nitrogen oxide metabolism and risk of developing endothelial dysfunc-tion in children with e-NOS 4a/4b gene polymorphism, who live under prolonged enter 137Cs to the body.

MATERIALS AND METHODS: There were examined 117 children-residents of radioactively contaminated territories and50 children of control group. The level of stable metabolites was defined in blood serum (NO2- and NO3-). The ther-mographic method was used to register the endothelium dependent reaction of the vascular bed to changes in theblood supply. The ventilation capacity of the lungs was evaluated using this method of pneumotachography.Polymorphism in intron 4 of the gene e-NOS was studied by the method of polymerase chain reaction. The contentof 137Cs in the body of children was determined using a human radiation counter Skrynner M-3.

RESULTS AND CONCLUSIONS: In children-residents of radioactively contaminated territories with genotype 4a/4b com-paring to children who had genotype 4b/4b, the decrease in the nitric content of in the blood serum, the increase inthe thermographic index of the recovery period of blood circulation to the baseline level after occlusion test werenoted, that is indicative of the decreased NO-synthase active of vascular endothelium in the carriers of the minorallele a in the 4th intron of gene eNOS (genotype 4a/4b), and is a risk factor for development of endothelial dysfunc-tion. It was proved a decrease in the index of lung tissue elasticity and stretchability - FVC / NFVC of the lungs com-paring to children with genotype 4b/4b, there was a reduction of integral index of respiratory tract permeability -FEV1/NFEV1. The inverse correlation dependence between the presence of allele a in the genotype and the values ofFVC/NFVC of the lungs (r = -0.259; p <0.05) and FEV1/NFEV1 (r = -0.2267; p <0.05) was found. Signs of bron-chospasm were found in the carriers of the allele a in 1.5 times more often than in children-carriers of homozy-gotes from allele b.