G.A. Zalesskaya, O.V. Laskina, N.P. Mitkovskaya, V.V. Kirkovsky

The aim of this study was to investigate the effect of UV blood irradiation (UVBI) on lipid metabolism in patients with acute coronary syndrome in whose combined therapy the extracorporeal UVBI was included. Hypolipidemic action of UVBI was evaluated by the level reductions for total cholesterol (TCH), low-density lipoprotein cholesterol (LDL-CH), high-density lipoprotein cholesterol (HDL-CH), triglycerides (TG) and atherogenity rate (AR). The high level of cholesterol in blood serum so-called hypercholesterolemia, is implicated as additional risk factors for heart disease. It was established that extracorporeal UVBI with exposure dose 0.06 J/cm2 caused alterations of lipoprotein-lipid levels, exhibiting in the reduction of average concentrations for TCH at 10.5 %, LDL-CH at 8.3 % and TG at 7.8 % whose concentrations were measured before and immediately after the end of 5 day treatment. It was happened that UVBI effect on cholesterol fractions proved to be varying strongly among various patients. From the analysis of the separate cholesterol fraction contents in blood of the individual patients the conclusions were made that their concentration changes initiated by UVBI depended on both the initial concentration in blood and the changes of hemoglobin oxygenation degree. The decrease of TCH and LDL-CH concentrations was registered at their high initial levels in the blood and contrariwise their concentrations became slightly higher after UVBI at low initial levels. Correlative analysis showed that average correlations were observed between CTCH and CTCH as well as CLDL-CH and CLDL-CH values (Pearcon linear correlation coefficients r = 0.70 and 0.72, respectively, P<0.01). It was established too that the positive changes of lipid metabolism under influence of UVBI took place only in such a case when degree of oxygen saturation of venous blood changed over the range 0<SO2<15 %. The dependences CTCH (SO2) and CLDL-CH (SO2) obtained were considered as analogue to dose dependences where changeable value SO2 outstands as «dose». The current knowledge about the mechanisms of hypolipidemic action of UVBI is insufficient. At the doses under consideration, the photodissociation of hemoglobin-oxygen complexes was considered by us as the most probable primary reaction initiated by the UVBI. We concluded from our studies that the photodissocia-tion of oxyhemoglobin altering the oxygen-carrying function of blood, improved oxygen supply to cell and tissues, corrected the processes generating the reactive oxygen species (ROS), as well. Therefore UVBI was considered as a method that regulates a balance between the ROS production and their inhibition by antioxidant systems. Conclusion was made that the concentration changes for TCH, LDL-CH and TG initiated by UVBI were stipulated by oxidative degradation of lipids under the influence of ROS-generating reactions as these active species induce a cascade of molecular reactions, resulting in the observed effects.