Morgenstern E, Ruf A, Patscheke H
Medizinische Biologie, Universität des Saarlandes, Homburg/Saar, Federal Republic of Germany.
Thromb Haemost. 1992 Jan 23;67(1):121-5.
The redistribution of the antibody-glycoprotein (GP) IIb/IIIa complex was investigated with the immuno-gold labeling technique in order to trace its transport in resting platelets. Washed platelets were incubated in the presence of aspirin and a prostacyclin analogue (iloprost) with three different monoclonal antibodies (Gi3, J15 and P2) against GPIIb/IIIa. The examination of ultrathin serial sections showed that the surface labeling was internalized into the surface connected membrane system (SCS). Labels were found within the alpha-granules after 40 min and the number of labels increased during longer incubation periods (max. 120 min). The transport possibly involved coated membranes. The alpha-granules were neither found to be altered during this process nor were any morphological signs of platelet activation detectable. The anti-GPIIb/IIIa complex remained membrane-associated during the transfer. These observations indicate that the membrane-GPIIb/IIIa complex was stable and transported from the surface into the alpha-granules of resting platelets. Since this transport was not influenced by iloprost or by aspirin it may be interpreted as constitutive endocytosis.
为追踪抗体 - 糖蛋白（GP）IIb/IIIa复合物在静息血小板中的转运，采用免疫金标记技术对其再分布进行了研究。将洗涤后的血小板与阿司匹林和一种前列环素类似物（依洛前列素）一起孵育，同时加入三种针对GPIIb/IIIa的不同单克隆抗体（Gi3、J15和P2）。对超薄连续切片的检查显示，表面标记物被内化到表面连接膜系统（SCS）中。40分钟后在α颗粒内发现了标记物，并且在更长的孵育时间（最长120分钟）内标记物数量增加。这种转运可能涉及被膜小泡。在此过程中未发现α颗粒发生改变，也未检测到血小板激活的任何形态学迹象。抗GPIIb/IIIa复合物在转运过程中始终与膜相关。这些观察结果表明，膜 - GPIIb/IIIa复合物是稳定的，并且从静息血小板的表面转运到α颗粒中。由于这种转运不受依洛前列素或阿司匹林的影响，因此可解释为组成型内吞作用。
