A study of the influence of different types of radioprotectors on the survival of mice treated with ionizing radiation over a wide dose range.

The subject of this study is the influence of the preventive administration of cystamine, naphthysin, Ukrain, Lymphokinin, Prodigiosan, and polyribonate on the 30-day survival of mice subject to doses of ionizing radiation ranging from LD50/30 to LD100/30. Conventional radioprotectors were shown to prevent the death of experimental animals irradiated with doses ranging from LD70 to LD100/30 but were inefficient as a means of preventing mortality at doses with a medium lethal effect. In contrast, the bioregulators Ukrain and Lymphokinin were more potent at doses ranging from LD50 to LD70/30 (1.5 times more potent than conventional radioprotectors). Polyribonate and Prodigiosan were the least potent. These findings are discussed with respect to the appropriateness of developing pharmacological means which could protect organisms from different degrees of radiation-induced damage. The need to modify the criteria for the selection of potential radioprotectors is emphasized.