Studies on chemical protectors against radiation, 14

Examinations were made on the relationship between the chemical structure of 47 kinds of sulfur-containing compounds, both SH-type and non-SH-type and toxicity to male ddY mice, and the protective effect of their lethal dose against X-irradiation. Among the compounds tested, 22 compounds were found to prolong the survival of X-irradiated mice, but there was no definite evidence for a relation between chemical structure and survival effect, or between toxicity and survival effect. Thiourea, methylthiourea, ethylenethiourea, methylisothiourea, and ethylisothiourea were found to be radioprotectors with a low toxicity.