Radioprotective effect of cystamine in mice locally irradiated in head region

Gamma irradiation of mice in the region of the head (1.38 Gy/min) brought about their death within 30 days at doses of 20 to 50 Gy. The administration of cystamine (150 mg/kg i.m.) 10 to 15 minutes before irradiation prevented the death of mice irradiated with a dose of 20 Gy. It was ineffective for higher doses. Irradiation of the heads of mice with doses of 10 to 50 Gy lowered the number of leukocytes in peripheral blood examined on the 3rd day after exposure. Except for the 20 Gy dose, prophylaxis with cystamine did not affect the number of leukocytes. A significant reduction in bone marrow cellularity on the 3rd day after irradiation of the head of mice with doses of 30 to 50 Gy was forestalled by prophylactic administration of cystamine. Cystamine also protected the mice from post-radiation decline in body weight observed during the 2nd week after the irradiation of heads with a dose of 20 Gy. Irradiation of the heads of mice with doses of 10 to 50 Gy did not affect the cellularity of the small intestine on the 3rd day after exposure