The megakaryocyte in thrombocytopenia: a microscopic study which supports the theory that platelets are produced in the pulmonary circulation.

Thrombocytopenia can increase platelet production and thereby facilitate investigations into the mechanism. Megakaryocytes in the bone marrow, lung, spleen and liver have been studied by light and transmission electron microscopy after 6 days of experimentally induced thrombocytopenia in the rabbit. The findings support the theory that platelets are produced in the pulmonary circulation by the physical fragmentation of megakaryocyte cytoplasm.