Megakaryocytopoiesis: incorporation of tritiated @entity1014 by small @entity4360 -positive cells in @entity19 bone marrow during antibody-induced XXXX .

@entity882 @entity894 @entity19 @entity665 @entity4360 @entity1014
The ability of small @entity4360 -positive (SACHE) cells to incorporate tritiated @entity1014 ( @entity665 ) was studied in the bone marrow of @entity19 made acutely @entity882 by injection of guinea pig antimouse platelet serum (APS) and in control @entity19 injected with normal guinea pig serum (NS). @entity665 was administered in vivo, and bone marrow was collected at various time points thereafter. The initial @entity894 ( @entity894 ) for both groups was about 30%. After four hours, the @entity894 increased and reached peak values at 48 hours, but was lower in @entity882 animals. The lower peak @entity894 in APS-treated animals may be the result of both a faster rate of influx of unlabeled cells into the @entity4360 ( @entity4360 ) positive cell compartment and efflux of more heavily labeled, and probably polyploid, SACHE cells into the compartment of recognizable megakaryocytes. In both groups the increasing @entity894 occurred concomitantly with a decreasing mean grain count. This may indicate cellular division by some fraction of SACHE cells. Heterogeneity in nuclear morphology was also demonstrated, and the frequency of individual morphologies was altered in APS-treated animals. In addition, cells that incorporated @entity665 were larger than those that did not. This group of small cells appears to represent a pivotal point in megakaryocytopoiesis in which the switch from mitosis to endomitosis is occurring.
