[Study of the dynamics of endogenous IL-6 in the culture erythroblastic islands].

It is found that in the process of cultivating the erythroblastic islets (EI) of rat bone marrow, the concentration of interleukin-6 (IL-6) increases in the culture medium. Stimulating erythropoiesis was observed on the 48th hour in cultures, the stimulation was characterized by the growth of endogenous erythropoietin and activation of formation of EI de novo and de repeto. The continuing increase in the concentration of IL-6 in the cultures at the 72nd hour of the experiment was accompanied by a decrease formation of islands de novo and a decrease in the absolute number of EI in culture.

[Effect of supernatant of erythroblastic island bone marrow cultures on erythropoiesis in vitro].

It was shown that joint cultivation of supernatants with bone marrow erythroblastic islands in liquid culture systems resulted in stimulatory or inhibitory effects on erythropoiesis. Influence of supernatants on erythropoiesis depended on the culture age, erythrocyte production in these cultures and duration of joint cultivation with bone marrow islands. Supernatants of 24 h cultures induced formation of erythroblastic islands de repeto and de novo in cultures.

[Dynamic changes of erythropoietin and tumor necrosis factor-alpha levels in peripheral blood and their correlation with erythropoiesis changes in posttransfusion polycythemia in animals].

Posttransfusion polyglobulia reveals elevated level of the tumor necrosis factor-alpha in peripheral blood, suppresses erythropoiesis in bone marrow erythroblastic islands by diminishing the newly forming erythroblastic islands, and suppresses erythropoietin production in rats.

[The investigation of dynamic changes of erythropoietin content of the erythroblast island cultures].

Dynamic changes of erythropoietin content on the 6th, 12th, 24 and 48th hours of cultivation in bone marrow erythropoietic island liquid short-term cultures were investigated. The initial doses of 0.25, 0.

[The effect of various stage maturity of erythrocytes upon proliferatio rate of erythroid cells in "crown" of erythroblastic islands].

Joint cultivation of small amounts of young and mature erythrocytes with bone marrow erythroblastic islands during 24 hours in liquid culture system results in erythropoiesis stimulation due to increase of number of cells in the state of mitosis in island's "crown". Prolonged joint cultivation and/or joint cultivation with plenty of premature and mature erythrocytes leads to inhibition of the erythropoiesis in the state of mitosis in the island's "crown". The maximum of the inhibitory effect was shown by erythrocytes from polycythemia rats.