摘要:

Previous light microscopic studies have revealed the erythroclastic potential of the rat bone marrow reticulum cells, and call for ultrastructural study of the finer details of this process. Electron microscopy of rat bone marrow which had been stimulated to increase its erythrophagic activity, either by splenectomy or by transfusion of heat‐denatured erythrocytes, confirmed the central reticulum cell of erythroblastic islands as the main phagocytic cell in bone marrow erythroclasia. The early digestive vacuoles, which are formed by the fusion of erythrophagic vacuoles with lysosomes, correspond to the acidophilic, globular structures which characterize erythrophagocytosis as observed by light microscopy. By forming intrasinusoidal protrusions, the bone marrow reticulum cells engulf circulating effete red cells. The engulfed red cells are then transported intracellularly across the sinusoidal wall for final disintegration in the intraparenchymal part of the reticulum cell. This transmural mode of erythrophagocytosis by reticulum cells most probably demonstrates the fundamental phagocytic mechanism of the bone marrow part of the reticulo‐endothelial system.Transmural transport of reticulocytes adherent to reticulum cells during the formation of protrusions illustrates a possible mechanism for liberation of red cells from the bone mar

ISSN:0036-553X    

DOI:10.1111/j.1600-0609.1975.tb01095.x

出版商:Blackwell Publishing Ltd    

年代:1975

数据来源: WILEY

摘要:

Intracellular transport and storage of iron in bone marrow reticulum cells can be studied in the electron microscope by the recognition of iron macromolecules. Following artificially increased bone marrow erythrophagocytosis ferritin molecules accumulate both in the cell sap and in the lysosomes of erythroclastic reticulum cells. Persistent iron loading transforms lysosomes into siderosomes, after which haemosiderin may be formed by gradual transformation of ferritin. The bone marrow reticulum cell shows evidence suggestive of autophagy, a process which may allow for the transfer of cell sap ferritin into lysosomes, as documented for other types of iron storing cells.

ISSN:0036-553X    

DOI:10.1111/j.1600-0609.1975.tb01096.x

出版商:Blackwell Publishing Ltd    

年代:1975

数据来源: WILEY