[The use of EPR spectroscopy to control the changes of organism radiosensitivity/radioresistance. Experimental and clinical results].

The responses of deoxyribonucleotide (dNTP), DNA and protein synthesis systems in blood-forming organs of animals (dogs, mice) as well as changes in Fe(3+)-transferrin (Fe(3+)-TF) and Cu(2+)-ceruloplasmin (Cu(2+)-CP) pools in blood to gamma-irradiation and the administration of radioprotectors have been studied. It has been shown that changes in Fe(3+)-TF and Cu(2+)-CP pools in blood are indices of changes in the body radioresistance and are reliably controlled by the EPR technique. An increase in the Fe(3+)-TF pool promotes the activated synthesis of dNTP, DNA and Fe(3+)-containing proteins which are essential for the repair efficiency during the early post-irradiation time as well as for the development of compensatory and restorative reactions of cellular systems; i.e., they are responsible for the body resistance to DNA-damaging factors. It is important that the intensity of responses depends on the initial state of the organism. It has been shown, that changes in Fe(3+)-transferrin and Cu(2+)-ceruloplasmin pools, which are trust-worthy controlled by the EPR technique in whole blood, blood plasma, and serum, as well as the changes in the extracellular DNA content in blood plasma are the markers of the changes in the organism radioresistance. This has been proved during the medical examination of the Chernobyl accident recovery workers and civil population, including children, exposed to low-intensity radiation.