Acute toxicity and radioprotective effects of amifostine (WR-2721) or cystamine in single whole body fission neutrons irradiated rats

Abstract

The radioprotective substances amifostine (WR-2721) and cystamine were tested in rats following their parenteral administration (i.p., i.m., and i.v.). Cystamine is more toxic than amifostine in mice as well as in rats. Amifostine was less toxic after intravenous injection. The radioprotective effects of WR-2721 (160 mg.kg-1) and cystamine (40 mg.kg-1) were not significant when they were administered parenterally 15 - 20 mins before lethal doses of whole body fission neutron irradiation in the thermal column of reactor VVR-S and 30-days lethality served as an integral criterion of postradiation injury to the rat body. The fission neutrons spectrum was characterized by mean energy 0.9-1.0 MeV with 30-40% fluency participation of moderate (E=0.1 MeV) neutrons. The contamination with gamma rays was 22-30 %; the dose rate of whole irradiation was within 0.3 to 0.8 Gy.min-1.