Cistiside-M, a new protective agent

The toxicological and radiopharmacological properties of the agent Cistiside-M (2-mercaptoethylamine adenosine-5-phosphate) were investigated on male mice, lines C57Bl and H. The compound was administered intraperitoneally in doses from 1000 to 125 mg/kg, 15 min prior to lethal gamma-irradiation using a 137Cs source in the 6 to 15 Gy range. The radioprotective effect was assessed by the integral indices of 30-day survival, mean survival time, coefficient of protection alpha, S30 and the dose-reduction factor (DRF). The compound was characterized by low toxicity and good antiradiation effect in a wide dose range. Maximum degree of radioprotection (75% survival) was established when the agent was administered in a dose of 1000 mg/kg. DRF was 1.6. The dose of 250 mg/kg was interesting--with 50% survival rate and increase of the therapeutic index to 5.6. The low toxicity and the considerable radioprotective effect of the compound are due to its complex structure.