Comparative Protective Effect of Cysteine against Fast Neutron and Gamma Irradiation in Mice

Abstract

Cysteine pretreatment was shown to confer significant protection against the acute lethal effects of gamma (Co60) and fast neutron (fission) irradiation in mice. The protection observed with fast neutrons is, however, about half of that found with gamma irradiation. The data presented support the concept of a true dose reduction in the sense that primary mechanisms are involved. The inverse relationship between protective efficiency and ionization density is comparable to that noted for the O2 effect and, for the present, may best be interpreted in terms of the spatial distr. of the radicals formed in water and their reactions.