[The effect of exogenous heparin on the processes of colony formation from myeloid precursors and the formation of erythroblastic islets].

Experiments were conducted on Wistar rats to study the comparative effect of exogenous administration of heparin (250 U) on the colony forming ability of committed myeloid precursors and the formation of erythroblast islets (EI). The results were recorded for 5 days. On the basis of the obtained data a primary selective effect of heparin on the granulocytic-macrophagal colony forming units in the diffusion chamber was revealed. The process of EI formation is affected only in the late periods (3rd-5th day) against the background of sharply stimulated myelopoiesis. A significant reduction of the number of EI is noted in this period.