Role of IL-1 and TNF in the ribomunyl-induced radio-protection.

Ribomunyl, an immunomodulating agent, administered to mice 24 h before irradiation, has a radioprotective effect. Ribomunyl enhances renewal of the hematopoietic tissues damaged by radiation. The results of our work have confirmed that IL-1 and TNF play a significant role in an earlier recovery of hematopoiesis induced by Ribomunyl administration in sublethally irradiated mice. Anti-IL-1 administration before that of Ribomunyl significantly reduced the CFU-GM increase in the bone marrow of mice on day 8 after irradiation with 6 Gy and prevented increase of the neutrophil granulocyte number in the peripheral blood. On the other hand, anti-TNF administration limited the CFU-S increase in the bone marrow and prevented a hematocrit increase in the peripheral blood.