[Ex vivo EPR investigation of metabolic changes in mice treated with radiotoxins]. / Issledovaniia metodom EPR ex vivo metabolicheskikh izmenenii v organizme belykh myshei pri vvedenii radiotokisnov.

The effect of radiotoxins (RT), obtained from gamma-irradiated potato tubers, on mice have been investigated using ex vivo EPR. Parts of liver, lung, spleen, heart and kidney were used for investigation. The amount of the preparations injected was 0.2 ml, RT concentration varying from 0.1 to 1 LD100 (LD100 = 100 mg/kg). An intraperitoneal injection of RT in dose of 0.1 LD100 resulted in metabolic changes only in spleen. During 8 hours after injection a gradual depression of enzyme ribonucleotide reductase activity in spleen has been observed. After the treatment of mice with a lethal dose of RT signals from nitrosyl complexes have been appeared in spectra from all tissue investigated. The intensities of lines depend both on a time passed after treatment and a sensitivity of tissue to RT action. One of the main reasons of the lethal outcome of mice treated with RT may be the breaking of the compensatory adaptive response due to enhanced hypoxic state resulting from the high concentration of nitrosyl complexes generated in the tissue.

[In vitro and ex vivo EPR investigation of metabolic changes in blood under the action of radiotoxins obtained from irradiated potato tubers]. / Issledovaniia metodom EPR in ivtro i ex vivo metabolicheskikh izmenenii v krovi pod deistviem radiotoksinov, poluchennykh iz obluchennogo kartofelia.

The effect of radiotoxin (RT) obtained from y-irradiated potato tubes on blood of sheep and mice has been investigated by using in vitro and ex vivo EPR. In experiments in vitro, the action of different preparations (RT, extract from unirradiated potato tubers, 1%-HCl or 30%-hydrogen peroxide) on sheep blood has been compared. It has been established that RT is an effective oxidant (like 1%-HCl) of haem iron that leads to an increase of the methemoglobin concentration. The specific peculiarity of RT effect on blood in vitro is an appearance of two well-resolved lines from methemoglobin belonging, probably, to different paramagnetic centers. The signal from nonspecific complexes of Fe3+ has been also observed. Ex vivo EPR spectra markedly differ from these obtained in experiments in vitro. An additional line with g approximately 2.005 and width 6 G in 30 minutes after intraperitoneal RT injection in the lethal dose (0.2 ml of preparation containing of 2 mg RT) has been revealed. Subsequent intoxication of mice is accompanied by the appearance of the signal from nitrosyl complexes in EPR spectra. These differences in experimental results of in vitro and ex vivo EPR can be explained by launch of compensatory adaptive response of organism on the action of highly toxic preparation.