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The mechanism of platelet release

J M Radley, G Scurfield

    Blood
    |December 1, 1980
    PubMed

    Insights

    Platelet release from megakaryocytes involves cytoplasmic processes constricting and rupturing to form platelets. This process, observed in mouse bone marrow, may share mechanisms with cell division.

    Area of Science:

    • Hematology
    • Cell Biology
    • Microscopy

    Background:

    • Megakaryocytes are large bone marrow cells responsible for producing platelets.
    • The precise mechanism of platelet formation and release remains an area of active research.

    Purpose of the Study:

    • To elucidate the ultrastructural mechanism of platelet release from megakaryocytes in mouse bone marrow.
    • To investigate the role of microtubules and centrioles in platelet formation.

    Main Methods:

    • Utilized scanning and transmission electron microscopy to examine mouse bone marrow.
    • Employed serial sectioning to identify cellular structures within cytoplasmic processes.

    Main Results:

    • Observed megakaryocyte cytoplasmic processes extending into sinusoids, undergoing attenuation, and forming constrictions of platelet size.
    • Identified microtubules concentrated at constriction sites, with the narrowest constrictions measuring approximately 0.2 micrometers in diameter.
    • Detected a centriole within each cytoplasmic process, suggesting a microtubule organizing center.

    Conclusions:

    • Platelet release likely occurs through the rupture of constricted cytoplasmic processes.
    • The mechanism of platelet release shares structural similarities with terminal cytokinesis, suggesting a common cellular release pathway.
    • Centrioles and associated microtubules may play a crucial role in regulating the formation and release of platelets, potentially influenced by megakaryocyte ploidy.

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