Hematology and Immunology
The liver hemopoietic environment: II. Peroxidase reactive mouse fetal liver hemopoietic cells
Article first published online: 8 FEB 2005
Copyright © 1983 Wiley-Liss, Inc.
The Anatomical Record
Volume 207, Issue 1, pages 43–53, September 1983
How to Cite
Medlock, E. S. and Haar, J. L. (1983), The liver hemopoietic environment: II. Peroxidase reactive mouse fetal liver hemopoietic cells. Anat. Rec., 207: 43–53. doi: 10.1002/ar.1092070106
- Issue published online: 8 FEB 2005
- Article first published online: 8 FEB 2005
- Manuscript Accepted: 29 APR 1983
- Manuscript Received: 2 NOV 1982
Through the combined use of peroxidase cytochemistry and examination at the ultrastructural level, the present study has identified liver hemopoietic foci containing three forms of erythropoietic cells, two forms of myelopoietic cells, and a population of peroxidase nonreactive cells within the extravascular compartments of mouse fetal liver. The nonreactive cells were 10 μm in diameter, displayed no peroxidase activity and were designated type I cells. This cell had an irregular nucleus, small profiles of rough endoplasmic reticulum (RER), a considerable population of monoribosomes and a few polyribosomes. The incidence of this cell type decreased significantly from 50% at 12 days gestation to approximately 10% of the hemopoietic cells at 17 days gestation. Type I cells could not be classified into a hemopoietic lineage and may represent undifferentiated hemopoietic stem cells. Three forms of erythropoietic cells, designated types II, III, and IV, were identified. These cells had a diffuse cytoplasmic peroxidase reaction, no peroxidase positive membrane-bound organelles, and were approximately 7 μm in diameter. They corresponded to the more classically defined proerythroblast, polychromatophilic erythroblast, and nucleated normoblast, respectively. Types II and III had moderate cytoplasmic reactions, whereas type III, in addition, had a slight nuclear reaction. Type IV cells had a very dense cytoplasmic reaction but no nuclear reaction. Of the myelopoietic cells detected, one form had a slightly reactive Golgi and a few reactive granules. The other form possessed a clearly positive nuclear envelope (NE), RER, Golgi, and a population of reactive granules. The phagocytic sinusoidal lining cells (Kupffer cells) were peroxidase negative in contrast to similar cells in the rat. A population of peroxidasepositive granules was detected in fetal liver developing hepatocytes at 17 days gestation and increased in number with age. The morphology and organization of these various cell types in the liver hemopoietic environment are discussed.