[Age-related characteristics of postradiation regeneration of the blood system]. / Vozrastnye osobennosti postluchevoi regeneratsii sistemy krovi.

This study was pursued on hybrid (CBA X C57Bl)F1 mice at the ages of 17 and 27 months irradiated at a dose of 4 Gy. It was shown that the postirradiation recovery of haemopoiesis in old mice was the same as in the young (2-3 month-old), and in some respects (for instance, granulocytic and erythroid cells of the bone marrow, and CFUc) the recovery was even more active exhibiting a period of a pronounced hyperregeneration.

[Effect of exposure to stress on the role of T- and B-lymphocytes in the response of the hematopoietic system]. / Rol' T- i B-limfotsitov v reaktsii krovetvornoi sistemy na stressornoe vozdeistvie.

Cellular composition of the bone marrow, spleen and peripheral blood was studied after 6-hour immobilization on the back in experiments on 4 groups of (CBAxC57BL)F1 mice with varying degree of T lymphocyte deficiency (thymectomy, sham thymectomy, administration of antilymphocytic serum, B mice). The evidence obtained shows that the "lymphoid peak" recorded in the bone marrow during stress is likely to be formed at the expense of T and B lymphocyte migration from the peripheral lymphoid organs. The data have been also obtained, indicating that T lymphocytes migrating to the bone marrow during the first 6-9 hours after the exposure to stress may participate in granulocytopoiesis activation.

[Quantitative characteristics of the phenomenon of acceleration of hematopoiesis regeneration in thymocyte transplantation]. / Kolichestvennaia kharakteristika fenomena uskoreniia regeneratsii krovetvoreniia pri transplantatsii timotsitov

Experiments were conducted on hybrid mice (CBA X C57BL) F1. The quantitative characteristics of the phenomenon of acceleration of postirradiation bone marrow regeneration in transplantation of syngenous thymocytes was given. It was revealed that in the range of 10(6)--10(8) cells the effect was independent of the number of transplanted thymocytes. The transplantation during the first 12 hours after the irradiation was equally effective from the aspect of stimulation of the bone marrow restoration. This phenomenon was not expressed under the following conditions: a) transplantation of thymocytes 24 hours after irradiation; b) irradiation of recipients in a dose of 600--700 R; c) irradiation of a thymocyte suspension in vitro in a dose of 10 kR with a subsequent incubation at 37 degrees C for 6--7 hours; d) irradiation of thymocytes in vitro in a dose of 200 kR.

[Effect of thymocyte autotransplantation on postradiation regeneration of hematopoiesis]. / Vliianie autotransplantatsii timotsitov na postluchevuiu regeneratsiiu krovetvoreniia

Experiments were conducted on Wistar rats irradiated in a dose of 400 R; a study was made of the effect of thymocyte autotransplantation (4-10(8)--8-10(8)) on the restoration of cell number of the bone marrow and the spleen. There was revealed a significant stimulating effect of autotransplantation of thymocytes on the erythroid and granulocytic series in the bone marrow and on the lymphoid one in the spleen during the restoration (the 5 th-- 7 th days) after the irradiation. Irradiation of the thymocyte suspension with gamma-rays in a dose of 10 000 R failed to prevent the effect of autotransplantation on the bone marrow, but decreased its stimulating effect. A conclusion was drawn on the interaction of the administered thymocytes with the stem hemopoietic cell.