[Study of the responses of tumor and normal tissues to exposure to ionizing radiation by the EPR method. I. Comparison of the low temperature EPR spectra of irradiated tumor and normal tissues].

ESR spectra of liver samples of normal mice and liver tumour samples of mice (line C3HA) injected hepatomo 22-a irradiated in the dose of 1 Mrad at --196 degrees C were studied. The ESR spectra of normal and tumour tissues irradiated at --196 degrees C are shown to differ. Only the ESR spectra of tumour and liver of the tumour host is characterized by an asymmetric signal with deltaH=6 Oe and g=2.0005 ("tumour" signal). The intensity of the "tumour" signal depends on the developmental stage of hepatoma. It is changed after the animals are injected with ionol.