Toxicological characteristics and primary radiobiological screening of Cystizid-M

The toxic and radioprotective properties of the potential radioprotector of the mollecular combination Cystisid-M (cysteamine-adenosin-5'-monophosphate - CAM) were investigated. The experiments were carried out on male mice C57BI irradiated with 137Cs source. The intraperitoneal administration of 1000 mg/kg b.w. and 500 mg/kg b.w., injected 15 min prior to the irradiation with 8,5 Gr (LD90/30) was performed, and orally 3000 mg/kg b.w. and 1500 mg/kg b.w. was introduced into the stomach 45 min prior to the irradiation with 8,2 Gr (LD83/30). The radioprotective effect of CAM was recorded according to: individual survival curves up to the 30th day; the biometrical coefficients 'ALPHA' (the individual survival expectancy in the population); and S30 (the group survival expectancy). At the intraperitoneal administration of the protector the values of LD50 = 1390 mg/kg b.w. and MPD (maximum permissible dose) = 1200 mg/kg b.w. were found. At the oral administration these doses were LD50/3 = 4630 mg/kg b.w. and MPD = 3500 mg/kg b.w. It was established that CAM injected intraperitoneally in a dose of 1000 mg/kg b.w. ensured 75% survival of the protected mice against 10% of the control ones, increased the mean survival of the deceased and reduced the percentage of the animals died during the height of the bone marrow syndrome. The twofold lower dose exetted a considerably slighter effect. At oral administration the protector did not significantly modify the survival of the animals. The data obtained revealed the perspectiveness of the tested protective agent radiobiological investigations are required