Meyer D
Nouv Rev Fr Hematol (1978). 1982;24(3):145-51.
von Willebrand Factor (vWF) is a high molecular weight multimeric (1-20 X 10(6) daltons) glycoprotein which is absent or inactive in von Willebrand's disease (vWD). It is synthesized by the endothelial cell under the control of an autosome and may be released into the blood stream as well as into the subendothelium (SE). vWF is also synthesized by the megacaryocyte and localized in the alpha granules of platelets. Platelet vWF is released during aggregation. Platelets do not adhere to intact endothelial cells but interact with the SE in case of vessel wall injury. vWF plays a key role in platelet adhesion to the SE, especially at high shear rate conditions which prevail in the microcirculation. This function is confirmed by the decreased platelet adhesion observed in either vWD blood (corrected by vWF) or normal blood in the presence of polyclonal or monoclonal antibodies to vWF. The mechanism of platelet adhesion to the SE is still poorly understood. vWF only acts at high shear, ie when the flow rate is elevated and the time of interaction between platelets and the vessel wall is short. This large protein could serve as a "bridge" between the platelet membrane and the SE. It has been shown to bind first to the SE prior to platelet adhesion. Platelet and endothelial cell vWF probably also interact since they may be released in high concentration at the site of injury. The nature of the SE component to which vWF and platelets bind is unknown. Among the candidates are the basement membrane and the collagen fibers (which adsorb vWF), fibronectin, and the microfibrils (which induce vWF-mediated platelet aggregation). It is thus possible that a receptor for vWF exists on one of these components. The ristocetin-induced platelet membrane receptor for vWF seems to be glycoprotein Ib, platelet adhesion being also abnormal in Giant Platelet Syndrome. The in vivo counterpart for ristocetin is unknown, but it is possible that collagen, microfibrils, thrombin (which also induces the platelet receptor for vWF or sialidases (asialo-human vWF is able to directly bind to the platelet membrane) could replace ristocetin. Several sources of data suggest that carbohydrate is important in vWF-platelet interaction.
血管性血友病因子（vWF）是一种高分子量多聚体（1 - 20×10⁶道尔顿）糖蛋白，在血管性血友病（vWD）中缺乏或无活性。它由常染色体控制下的内皮细胞合成，可释放到血流以及内皮下层（SE）中。vWF也由巨核细胞合成并定位于血小板的α颗粒中。血小板vWF在聚集过程中释放。血小板不粘附于完整的内皮细胞，但在血管壁损伤时与内皮下层相互作用。vWF在血小板粘附于内皮下层中起关键作用，尤其是在微循环中占主导的高剪切速率条件下。在vWD血液（用vWF纠正）或存在针对vWF的多克隆或单克隆抗体的正常血液中观察到的血小板粘附减少证实了这一功能。血小板粘附于内皮下层的机制仍知之甚少。vWF仅在高剪切力时起作用，即当流速升高且血小板与血管壁之间的相互作用时间短时。这种大蛋白可作为血小板膜与内皮下层之间的“桥梁”。已证明它在血小板粘附之前先与内皮下层结合。血小板和内皮细胞vWF可能也相互作用，因为它们可能在损伤部位以高浓度释放。vWF和血小板所结合的内皮下层成分的性质尚不清楚。候选成分包括基底膜和胶原纤维（吸附vWF）、纤连蛋白以及微原纤维（诱导vWF介导的血小板聚集）。因此，这些成分之一上可能存在vWF受体。瑞斯托菌素诱导的vWF血小板膜受体似乎是糖蛋白Ib，在巨大血小板综合征中血小板粘附也异常。瑞斯托菌素在体内的对应物尚不清楚，但胶原、微原纤维、凝血酶（也诱导vWF血小板受体）或唾液酸酶（脱唾液酸人vWF能够直接结合到血小板膜）有可能替代瑞斯托菌素。若干数据来源表明碳水化合物在vWF - 血小板相互作用中很重要。
