Kaplan K L, Owen J
Blood. 1981 Feb;57(2):199-202.
Measurement of plasma levels of two secreted platelet proteins (beta-thromboglobulin and platelet factor 4) has been suggested as a means for detecting increased platelet activation in vivo. A crucial question in the measurement is the distinction between in vivo and in vitro secretion of the proteins. One approach to this distinction is the measurement of both proteins in each sample. These proteins are present in platelets in similar amounts and are released in similar quantities, but the plasma levels of beta-thromboglobulin exceed the plasma levels of platelet factor 4. This difference in plasma level is presumably due to more rapid removal of platelet factor 4 from the plasma level, and there is suggestive evidence that the rapid removal of released platelet factor 4 is due to its binding to endothelial cells. It appears that when there is increased release of beta-thromboglobulin and platelet factor 4 in vivo, there is an increase in the ratio of plasma beta-thromboglobulin to plasma platelet factor 4 compared to that found in normal individuals, whereas when in vitro release is responsible for elevated levels, the ratio decreases. Thus measurements of both proteins in each blood sample will allow distinction between in vivo release and artefactual in vitro release.
测量两种分泌型血小板蛋白（β-血小板球蛋白和血小板第4因子）的血浆水平已被提议作为检测体内血小板活化增加的一种方法。该测量中的一个关键问题是区分这些蛋白质的体内分泌和体外分泌。区分的一种方法是在每个样本中测量这两种蛋白质。这些蛋白质在血小板中的含量相似，释放量也相似，但β-血小板球蛋白的血浆水平超过血小板第4因子的血浆水平。血浆水平的这种差异可能是由于血小板第4因子从血浆中被更快地清除，并且有提示性证据表明，释放的血小板第4因子被快速清除是由于其与内皮细胞结合。似乎当体内β-血小板球蛋白和血小板第4因子的释放增加时，与正常个体相比，血浆β-血小板球蛋白与血浆血小板第4因子的比值会增加，而当体外释放导致水平升高时，该比值会降低。因此，在每个血样中测量这两种蛋白质将有助于区分体内释放和人为的体外释放。
