Analysis of megakaryocyte ploidy in rat bone marrow cultures
DJ Kuter, SM Greenberg and RD Rosenberg
Department of Biology, Massachusetts Institute of Technology, Cambridge
02139.
Megakaryocytes undergo changes in ploidy in vivo in response to varying
demands for platelets. Attempts to study the putative factor(s) regulating
these ploidy changes have been frustrated by the lack of an appropriate in
vitro model of megakaryocyte endomitosis. This report describes a culture
system in which rat bone marrow is depleted of identifiable megakaryocytes
and enriched in their precursor cells. Morphologically identifiable
megakaryocytes appear when the depleted marrow is cultured in vitro. The
total number of nucleated cells, as well as the number of megakaryocytes
and their ploidy distribution, are quantitated very precisely by flow
cytometry. Although the total number of nucleated cells declines by 35% to
40% over 3 days in culture, the number of megakaryocytes rises 10-fold. The
number of nucleated cells, the number of megakaryocytes, and the extent of
megakaryocyte ploidization behave as independent variables in culture and
are dependent on the culture conditions. The addition of recombinant
erythropoietin promotes a rise in the number of megakaryocytes and a shift
in ploidy to higher values while recombinant murine granulocyte- macrophage
colony stimulating factor is without effect on the cultured megakaryocytes.
This in vitro system may provide a means to study those factors that affect
megakaryocyte growth and ploidization.
Volume 74,
Issue 6,
pp. 1952-1962,
11/01/1989
Copyright © 1989 by The American Society of Hematology
