G.A. Zalesskaya, O.V. Laskina

The primarily molecular mechanisms of photophysical processes determining the biological and therapeutic effect of ultraviolet irradiation of autotransfused blood are investigated in this work. Intravenous irradiation of blood by UV light with =254 nm is employed to investigate the influence of UV light absorption by blood on hemoglobin and oxygen transport for patients with acute coronary syndrome. The objects of the research are the spectral, biochemical characteristics of venous blood, the data of oxymetry and gas content as well as changes in oxygen utilization and metabolism. To identify the molecular photoacceptor and mechanisms of primary photoreaction the spectral data are used both in visible and infrared regions. The conclusion about determining role of hemoglobin photodissociation is made on the basis of the results of spectral changes in the UV-visible absorption bands of hemoglobin (spectrum where the Sore band maximum is shifted by a few nanometers towards the lower wavelengths) due to transition of oxyhemoglobin in deoxyhemoglobin after light absorption of blood. In IR spectrum it was found that the bands of polypeptide bone are sensitive to the conformational transitions associated with the ligand loss. The important role of the photodissociation of oxyhemoglobin after UV light absorption is confirmed with changes: gas compound , oxyhemoglobin fraction, oxygen capacity in venous blood induced by the UV light absorption. It was found that growth of oxygen partial pressure, decrease in oxyhemoglobin fraction takes place in venous blood under the influence of UV radiation. The primary reaction does not produce any change values pH as well as concentrations of сarboxyhemoglobin and methemoglobin indicating the absence of hemoglobin oxidation within erythrocytes at therapeutic doze of UV blood irradiation. According to data of transcutaneous oximetry, the moderate rise in oxygen saturation of the arterial blood is found. These data evidence an increase in oxyhemoglobin fraction, oxygen capacity in arterial blood under the influence of UV radiation. As consequence, the oxygen delivery and consumption increase. On the basis of given and earlier received data the conclusion has been made that hemoglobin phototransforma-tion is the most important photoprocess with point of view of biostimulation which is capable to cause (the photobiological and therapeutic effects) the improvement in oxygen delivery and consumption, rice in circulation. Consecutive changes of intacellular oxygen concentration induced by UV blood irradiation regulate the generation of reactive oxygen species which, as it is known in turn initiate some very exceptional biochemical events.