Scanning electron microscope study of platelet release by canine megakaryocytes in vitro.
Megakaryocytes were isolated from bone marrow from healthy dogs, using a combination of density-gradient centrifugation and polysucrose-velocity sedimentation techniques. The 2-step separation technique resulted in a preparation comprising 30% to 35% megakaryocytes of total nucleated cells. Accessibility to large numbers of viable canine megakaryocytes allowed investigation of platelet release by these cells in short-term cultures. Megakaryocytes were observed to form long cytoplasmic processes that gradually developed segmental constrictions and subsequently fragmented into platelet-sized pieces. Some platelet-sized cytoplasmic pieces of megakaryocytes presumably underwent discoid transformation.
D000818:Animals; D001792:Blood Platelets / Q000648:ultrastructure*; D001854:Bone Marrow Cells; D002499:Centrifugation, Density Gradient; D004285:Dogs / Q000097:blood*; D008297:Male; D008533:Megakaryocytes / Q000648:ultrastructure*; D008855:Microscopy, Electron, Scanning