IMMATURE MEGAKARYOCYTES IN THE MOUSE - MORPHOLOGY AND QUANTITATION BY ACETYLCHOLINESTERASE STAINING

  • 1 January 1981
    • journal article
    • research article
    • Vol. 58  (5) , 1032-1039
Abstract
Three types of immature megakaryocytes, detected by their morphological properties, were characterized in bone marrow of normal C57BL[fibrosarcoma neoplastic cell line]/6 mice. Morphological classification of these cells was carried out by determining presence and relative amount of acetylcholinesterase, cell size, nuclear:cytoplasm ratio and nuclear shape. The immature megakaryocytes were classified as: cells distinguished by a round nucleus (10.6 .+-. 1.1 .mu.m diameter; mean .+-. SEM), which had the highest nucleus:cytoplasm ratio and lowest content of acetylcholinesterase; cells with an indented nucleus (13.0 .+-. 1.9 .mu.m diameter), which had increased acetylcholinesterase content and reduced nucleus:cytoplasm ratio compared to the round-nucleus cell type; and lobed-nucleus cells (14.5 .+-. 2.9 .mu.m diameter), which showed further increase in acetylcholinestrase content and reduction in nucleus:cytoplasm ratio. Increased numbers of immature megakaryocytes were detected, indicating that a proportion of these cells are undetected using conventional staining techniques. Based on the observed alterations in size, acetylcholinesterase content and nuclear complexity, these cells apparently constitute part of a progressive maturation sequence intermediate between the progenitor cell (CFU-Mk) and mature easily recognizable megakaryocytes.