[The cellular and humoral mechanisms of the radioprotective action of prodigiozan and indometofen on long-term mouse bone marrow cultures].

Effects of prodigiosan and indometophen on the contents and proliferative activity of CFU and CFU-GM as well as GM-CSF prior to radiation were studied in long-term cultures of murine bone marrow. 24 hours and 5 days after administration of prodigiosan and indometophen, respectively, the long-term cultures were exposed to ionising radiation in a dose 2.0 Gy.

[The study of mechanisms of radioprotective action of indometofen n hematopoietic stem cells in mouse long-term bone marrow cultures].

The influence of indometophen (an analog of tamoxiphen) on the dynamic content and the proliferative activity of CFUs (colony-forming units) and CFU-GM (granulocyto-macrophages precursors) and the level of colony-stimulating factor (GM-CSF) in mouse long-term bone marrow cultures were studied for 4 weeks after administration. Five days after indometophen injection the long-term cultures were exposed to irradiation with a dose of 2 Gy and on the time course of postirradiation recovery haemopoietic precursors cells and dynamic release of GM-CSF in the culture supernatants were examined. The data of this report suggest that the mechanisms responsible for the radioprotective action of indometophen may be associated both with its direct effects on the proliferation and differentiation of hemopoietic cellular precursors and with the stimulation of release of growth-differential factors by hemopoietic microenvironmental elements.

[Effects of emotional stress on postradiation regeneration of the hematopoietic system in rats under protective action of indralin].

The rat experiments were designed to study the effect of the emotional stress, developed before or after gamma-irradiation with a dose of 6.0 Gy (LD40-50/30), on the radioprotective effectiveness of indralin. It was shown that the emotional stress, developed before irradiation, did not change the radioprotactive effect of indralin on hemopoietic system.

[Role of T-lymphocytes in impaired adaptive reaction of the hemopoietic system in emotional stress developed after preliminary gamma-irradiation].

Murine experiments demonstrated the inhibitory action of gamma-pre-radiation in a dose of 0.9 Gy on the progression of bone marrow hyperplasia to a resistant stage of the general adaptive syndrome in emotional stress. Intact thymocyte grafting recovered this reaction.

[Mechanism of radioresistance of the hematopoietic system after treatment with diethylstilbestrol].

The effect of diethylstilbestrol on the hematopoietic system of intact animals and on dynamics of post-radiation hematopoiesis recovery was studied. The injection of diethylstilbestrol into unirradiated animals was shown to induce the decrease in CFUs and CFU-GM content in bone marrow, the increase in granulocyte-macrophage precursors number in spleen, the decrease in proliferative activity of hematopoietic precursor cells and the rise of CSF-GM levels in the sera at the period of optimal manifestation of radioprotective effect. Mice, which were protected by diethylstilbestrol, demonstrated much more powerful recovery of CFUs, CFU-GM numbers as well as myeloid and erythroid hematopoiesis series in comparison with irradiated control animals.

[Analysis of cellular and humoral mechanisms of the anti-radiation action of the drug HC-1539].

The agent HC-1539, an analogue of tamoxifen, was studied for its effects on the blood system of intact animals and on the time course of postradiation recovery of hemopoiesis. HC-1539 given to the mice unexposed to radiation reduced bone marrow levels of CFUs (a colony of forming units in the spleen) and CFU-GM (that in the granulocyte-macrophages) and increased splenic counts of granulocyte-macrophage precursors. There was also a decrease in the proliferative activity of CFU-GM 1 and 5 days after the drug administration and an increase in serum GM-CCP levels when the agent showed the peak of its radioprotective effect.