Search

A series of amino and guanidino thiols and thiol derivatives has shown a parallelism between their radiation-protective abilities in mice and their ability to inhibit the metalloenzyme catalase. Exceptions were found with a dithiocarbamate, which has higher metal-binding strength than the thiols, and a thiosulfate, which has weaker metal-binding ability. Inhibition of two forms of lactate dehydrogenase, where metal binding is unlikely, showed no correlation with radiation protection. This suggests that protection of catalase from radiation damage by agents that complex with the iron constituent constitutes one means of protecting animal cells from radiation-produced peroxides.