ON THE MECHANISM OF CYSTAMINE (2-AMINOETHYLDISULFIDE) RADIATION PROTECTION

The relations between the protective effects of cystamine, the oxygen content in tissues, and inhaled oxygen were studied in 8- to 12-week-old white mice weighing 18 to 20 g, Mice were injected with cystamine 15 min before exposure to 700 to 900 r of y rays at 236 r/min. It was found that 5 mg of cystamine injected either intravenously or intraperitoneal prevented lethality after 900 r. Cystamine penetrates Erlich ascites cancer cells in approximately the same quantity in vivo and in vitro. However, its protective effects are active only in vivo. It was considered that the protective qualities of cystamine are the products of its transformation in the organism into cysteamine. (R.V.J.)