[Structure of ectopic foci of hematopoiesis in the mouse].

By means of light and electron microscopic methods foci of ectopic hemopoiesis have been investigated. They are formed on acetate-cellulose (AC) membranes implanted into the mice peritoneal cavity and into the mesentery after radiation and intraperitoneal injection of a donor's bone marrow. On the surface of the AC-membranes predominantly granulocytic differentiation of hemopoietic colonies is observed, prevalence of fibroblasts in the sublayer composition, absence of contacts of hemopoietic elements of the colonies with cells of the sublayer. In the mesentery mixed hemopoietic colonies of the donor's origin are revealed consisting of elements of granulocytic, macrophagal and megakaryocytic lines of differentiation. In the mesenteric colonies there are noted mesothelial cells, lipocytes, macrophages, and reticular cells having contacts with hemopoietic cells. The role of the sublayer cells for formation and differentiation of the hemopoietic foci in the experimental systems studied is discussed.