Proliferation kinetics and lethality after irradiation; modification by radioprotection.

By means of radioprotection, it was shown that a correlation exists after LD 50/30 between radiation-induced changes in cellular proliferation of critical radiosensitive tissue (bone marrow) and lethality, both in the time course and in the degree of the effect. Close correspondence between proliferation changes after irradiation and radiation lethality indicates that the inhibition of proliferation activity may play a major role in the mechanism of the death of irradiated organisms. A modification of cellular proliferation results in a change in radiation mortality. Pretreatment with the radioprotective compound AET leads to a moderation of both the inhibitory effect of radiation upon proliferation and radiation lethality.