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The effects of an pretreatment course (2 x 5 days) combining vitamin E 20 mg/kg, anthocyans 50 mg/kg, and pyracetam 200 mg/kg on animal survival after lethal irradiation (8 Gy) and blood formation after sublethal irradiation (6 Gy) were studied in mice. Assessments were based on records of an integral criterion, 30-day survival, of spleen weight and cellularity, and of bone-marrow cellularity. Pretreatment with the mixture distinctly raised survival rate (50%) in the protected population. The effect observed was shown to result from potentiating interactions between mixture components. Blood-forming organs experienced less radiation damage, and recovery processes in them were stimulated.

Experiments were carried out to investigate the possibility of providing chemical protection to blood forming organs and increasing animal survival rates in lethally irradiated H mice and Wistar rats. A 300 mg/kg dose of the radioprotective agent was injected intraperitoneally 15-30 min prior to irradiation with 8.0 Gy gamma rays. Recorded were 30-day survival rates and the state of hemopoiesis on days 3 and 10 postradiation as judged by spleen weight and total counts of spleno- and myelokaryocytes. At 8.0 Gy exposure was observed to cause severe spleen and bone-marrow hypoplasia on day 3 postradiation. Adeturone pretreatment provided slight protection to rat spleen and mouse bone marrow; by day 10, however, both animal species exhibited a vigorous proliferative response of nucleated cells in the bone marrow, which resulted in 75% survival rate among animals exposed to a lethal radiation dose.

The effect of successive prophylactic administration of the adaptogen Eleutherococcus and the chemical radioprotector Adeturone on the radiation injury in rats is investigated. The experiments were carried out on sexually mature male Wistar rats weighing 170 +/- 10 g. For 14 days the animals drank water containing Eleutherococcus extract (Medexport), 5 g/kg body weight. On the 7th and 14th days the daily dose of the extract was administered totally using a probe. One hour prior to the last intake, the rats were irradiated with 3 Gr using a 137Cs source, 15 min earlier part of them were injected intraperitoneally with 300 mg/kg Adeturone. The effect of the independent and successive administration of the two agents on the postradiation damage and recovery was tested on the 1st, 3rd, 10th, 20th and 30th days after the irradiation by the change in the leucocyte count and in the quantity of nucleic acids in the leucocytic mass of the blood. The independent application of the adaptogen and radioprotector have a favourable effect only on the course of the recovery processes. Successive administration of the two agents results in mutual potentiation of the effects and guarantees a high degree of protection. This is probably due to an increase in the natural radiation resistance and to the rats' capacity for adaptation during the acute phase of the radiation stress.

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.