[Effect of aminopropyl-aminoethylthiphosphate on radio-iron utilization following whole-body irradiation of mice in the sublethal dose range].

The effectiveness of the thiophosphate compound WR 2721 was investigated with regard to the radiosensitivity of X-irradiated female mice in the sublethal dose range of 50 to 150 R using the radioiron test (59Fe). An increase of the radioresistance with regard to the radioiron uptake in young erythrocyte populations was obtained only beyond radiation doses of 75 R. In lower dose ranges the animals treated with thiophosphate became even more radiosensitive. At dose values of 100 R and 150 R dose reduction factors (DRF) of 1.3 and 1.5 respectively were obtained. These factors are considerably smaller than the DRF-values found for the survival rate at LD 50/30. A possible mechanism for this result may be due to the different dephosphorylation rate of the thiophosphate in various tissues, as described in literature.