Department of Medicine, King's College School of Medicine, London.
Platelets. 1991;2(1):11-7. doi: 10.3109/09537109109005497.
Platelets are produced from megakaryocytes. Under normal physiological conditions changes in platelet volume and density are not secondary to ageing but are present at thrombopoiesis. Prolonged increased platelet destruction rate leads to the production of large platelets from large, high ploidy megakaryocytes. In vivo and ex vivo studies show such platelets have more haemostatic potential. Platelets are larger and denser in acute myocardial infarction, where bleeding time is shortened and bleeding time aspirin sensitivity is increased. Thromboxane A(2) formation is increased in unstable angina pectoris and in acute myocardial infarction. Megakaryocytes are enlarged in acute myocardial infarction and in sudden unexpected cardiac death. Megakaryocyte and platelet changes may precede coronary artery thrombosis.
血小板由巨核细胞生成。在正常生理条件下，血小板体积和密度的变化不是衰老的继发反应，而是在造血过程中就存在。血小板破坏率持续升高导致从大的、高倍体的巨核细胞产生大的血小板。体内和体外研究表明，这些血小板具有更高的止血潜能。在急性心肌梗死中，血小板更大、更密集，出血时间缩短，阿司匹林敏感性增加。不稳定型心绞痛和急性心肌梗死中血栓烷 A2 的形成增加。巨核细胞在急性心肌梗死和突发性心脏骤停中增大。巨核细胞和血小板的变化可能先于冠状动脉血栓形成。
