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Erythroid cell growth from normal and W/WV murine bone marrow on macrophage-coated membranes
Abstract:
Cellulose acetate membranes (CAM) placed in the peritoneal cavity of mice develop a macrophage layer capable of supporting in vivo hematopoietic colonies from intraperitoneally injected bone marrow cells. Modifications allowing for routine morphologic identification of colonies showed that both erythrocytic (E) and granulocytic (G) colonies occur with a consistent E:G ratio of 0.19 +/- 0.037. Stimulating recipients by bleeding or phenylhydrazine injection did not produce a significant change in the total number of colonies and a reduction in granulocytic colonies so that the E:G ratio significnatly increased. Hypertransfusion of donor animals had no effect on the number of erythroid colonies that grew on CAM of average recipients. The total colony-forming ability of bone marrow cells from genetically anemic W/WV mice was found not to differ from that of normal +/+ littermates; however, the E:G ratio of W/WV marrow in bled recipients was significantly lower (p less than 0.01) then that of +/+ marrow. These studies suggest that a CAM system supports an erythroid progenitor which is not affected by hypotransfusion of the donor animal, yet is dependent upon erythropoietin for colony formation, and that it is defective in the W/WV mouse.
Insights
Cellulose acetate membranes (CAM) support hematopoietic colonies in vivo. The CAM system reveals an erythroid progenitor dependent on erythropoietin and defective in W/WV mice.
Area of Science:
- Hematology
- Immunology
- Cell Biology
Background:
- Cellulose acetate membranes (CAM) in the peritoneal cavity attract macrophages.
- These macrophages support in vivo hematopoietic colony formation from injected bone marrow cells.
Purpose of the Study:
- To characterize the hematopoietic colonies forming on CAM.
- To investigate the erythroid and granulocytic progenitor populations.
- To assess the role of erythropoietin and genetic anemia in this system.
Main Methods:
- Implantation of CAM into mouse peritoneal cavities.
- Injection of bone marrow cells.
- Morphological identification of erythrocytic (E) and granulocytic (G) colonies.
- Manipulation of recipient erythropoiesis (bleeding, phenylhydrazine, hypertransfusion).
- Use of bone marrow from normal (+/+) and genetically anemic (W/WV) mice.
Main Results:
- Consistent erythrocytic to granulocytic (E:G) colony ratio of 0.19 +/- 0.037 was observed.
- Stimulation of erythropoiesis increased the E:G ratio by reducing granulocytic colonies.
- Hypertransfusion did not affect erythroid colony numbers.
- W/WV mouse bone marrow showed a significantly lower E:G ratio in bled recipients compared to normal marrow.
Conclusions:
- The CAM system supports an erythroid progenitor responsive to erythropoietin but not hypertransfusion.
- This progenitor is defective in W/WV mice, indicating a role for the W gene in erythropoiesis.
- The CAM model is valuable for studying hematopoietic progenitor function and regulation.