[The role of hematopoietic microenvironment in prodigiozan' mechanism of action on postradiation recovery of hemopoiesis in long-term bone marrow cultures].

Influence of prodigiozan in different concentrations on the process of postirradiation recovery of haemopoietic precursors (GM-CFC) and morphologically recognizable elements of the bone marrow were studied in long-term bone marrow cultures during 28 days after 2 Gy gamma-irradiation. Also, prodigiozan was studied for action on the contents of GM-CFC and induction of GM-CSF three, 24 and 48 hours after injection in cultures unexposed to radiation. It is shown that injection of prodigiozan in concentration 0.1-1.0 microg/ml 24 hours prior to irradiation stimulates postradiation recovery of GM-CFC number and a total number of myelocaryocytes in irradiation of long-term bone marrow cultures. In saved cultures there was an increase in the number of stromal cells 1 and 2 days after radiation. In non-exposed to radiation long-term bone marrow cultures injection of prodigiozan increased induction of GM-CSF and raised contents of GM-CFC. The maximal increase occurred 24 hours after introduction of radioprotector. It is suggested that one of the mechanisms of a radioprotective action of prodigiozan may be stimulation of hematopoietic microenvironment cellular elements leading to a marked release of GM-CSF or/and other cytokines and stimulation of recovery of hemopoietic precursors.