[Clonogenic hematopoietic cells (CFU-S) of mouse embryonic liver during short-term in-vivo cultivation].

The stem cell compartment of hemopoietic clonogenic cells (CFU-S) of mouse embryos in a closed system was studied, when the hemopoietic tissue was devoid of supply of the hemopoietic cells and grafted into adult recipients with diverse regulatory influences. The content of hemopoietic clonogenic cells (CFU-S-7, CFU-S-11, and CFU-S-el) was determined in the transplants of the 14-day embryonic liver placed under the renal capsule of preirradiated syngeneic adult recipients. Relatively younger clonogenic cells (CFU-S-11) were practically absent from the transplant in the end of cultivation, while the more advanced stages (CFU-S-7) became more abundant.

[The effect of 5-fluorouracil on the clonogenic hematopoietic cells (CFU-S) of embryonic and sexually mature mice].

We studied sensitivity of various types of clonogenic hemopoietic cells (CFU-S-7, CFU-S-11, and CFU-ep) on the liver of 14-days embryos and from the bone marrow and spleen of adult mice to the cytotoxic agent 5-fluorouracil (5-FU) in vitro and in vivo. We discovered that different types of CFU-S of the embryos and adult mice has similar sensitivity to 5-FU in vitro. At the same time in vivo the bone marrow CFU-S-7 display a higher sensitivity to 5-FU than CFU-S-11, thus agreeing with the published data (Hodgson and Bradley, 1979).

[Clonogenic hemopoietic cells (CFU-S) in mouse pre- and postnatal ontogeny].

Content of three classes of clonogenic haemopoietic cells (CFU-S-7, CFU-S-11 and CFU-S-ep) was determined in haemopoietic organs of mouse during embryogenesis (10, 14 and 18 day) and postnatal ontogenesis (2, 3 and 7 day, 1, 2, 3 and 18 month). CFU-S-7 and CFU-S-11 that from big splenic colonies on 7th and 11th days of transplantation are present in liver, spleen and bone marrow at all developmental stages. However their concentration and CFU-S-7 CFU-S-11 ratio change in haemopoietic organs.

[Histological study of splenic colonies at different times following the transplantation of hematopoietic cells from embryonic liver].

Histological analysis was carried out on the hemopoietic spleen colonies within 7 and 11 days after transplantation of the embryonic liver cells. Large superficial colonies were always present and were, predominantly, erythroid and mixed. Small superficial colonies consisted of undifferentiated cells and, unlike large colonies, appeared on the 11th day only.

[Existence of pre-CFU-S in the liver of mouse embryos].

Two types of CFU-s different in the size of their colonies have been found in the liver of 14 day old mice embryo. Statistic processing of the data allowed to prove that large spleen colonies are formed directly by CFU-s, whereas small colonies are formed by pre-CFU-s which undergo preliminary proliferation and only the stochastically differentiate into CFU-s. Approximate concentration of pre-CFU-s constitutes 2.