Michelson A D, Adelman B, Barnard M R, Carroll E, Handin R I
Department of Pediatrics, University of Massachusetts Medical School, Worcester 01655.
J Clin Invest. 1988 Jun;81(6):1734-40. doi: 10.1172/JCI113513.
Platelet membrane glycoprotein (GP) Ib contains receptor for von Willebrand factor and thrombin. Its proteolytic fragment, glycocalicin, circulates in normal plasma. In this study, storage of platelet concentrates for 5 d resulted in a 221% increase in plasma glycocalicin (1.3 times the total amount of glycocalicin present on the surface of all platelets), an 8% overall increase in platelet surface GPIb, and the appearance of a surface GPIb-negative subpopulation of platelets. Total platelet GPIb content of fresh washed platelets, determined by gel electrophoresis and immunoassay of Triton X-100 lysates, averaged 159,740 molecules per platelet. There were 36,360 surface GPIb molecules per platelet, determined by immunoassay of the supernatant of fresh washed platelets whose surface GPIb had been completely plasmin-cleaved. In summary, these studies provide evidence for (a) a redistribution of GPIb molecules with platelet storage, and (b) a large intraplatelet pool of GPIb (approximately threefold larger than the platelet surface pool of GPIb).
血小板膜糖蛋白（GP）Ib含有血管性血友病因子和凝血酶的受体。其蛋白水解片段糖萼蛋白在正常血浆中循环。在本研究中，血小板浓缩物储存5天导致血浆糖萼蛋白增加221%（是所有血小板表面糖萼蛋白总量的1.3倍），血小板表面糖蛋白Ib总体增加8%，并出现了血小板表面糖蛋白Ib阴性亚群。通过对Triton X-100裂解物进行凝胶电泳和免疫测定，新鲜洗涤血小板的总血小板糖蛋白Ib含量平均为每血小板159,740个分子。通过对表面糖蛋白Ib已被纤溶酶完全裂解的新鲜洗涤血小板上清液进行免疫测定，每血小板有36,360个表面糖蛋白Ib分子。总之，这些研究为以下两点提供了证据：（a）糖蛋白Ib分子随血小板储存发生重新分布；（b）血小板内存在大量糖蛋白Ib池（大约比血小板表面糖蛋白Ib池大三倍）。
