Chemical protection and sensitization to ionizing radiation molecular investigations

The main classes of radioprotective and radiosensitive drugs include compounds with respectively reducing and oxidizing properties towards the radiation induced radicals derived from biological materials. Some significant examples of the application of radiation chemistry to chemical radioprotection and radiosensitization are illustrated. Specifically, the mechanisms of radioprotection offered by -SH compounds are discussed as are the mechanisms of radiosensitization produced by strongly electronaffinic compounds. The results demonstrated the important role played by molecular phenomena for the interpretation of mechanisms of chemical radioprotection and radiosensitization and for the development of more active substances. Much of the information concerning the involvement of fast processes in chemical radioprotection and radiosensitization is derived from studies of simple model chemical and cellular systems carried out with fast radiation chemical techniques. (UK)