Wang M
Institute of Hematology, CAMS, Tianjin.
Zhongguo Yi Xue Ke Xue Yuan Xue Bao. 1993 Oct;15(5):339-42.
Calcium plays a central role in platelet activation. Calcium changes in acquorin-loaded human platelets induced by monoclonal antibodies (McAbs) were recorded using a PIGA-apparatus. McAb Apt4 is specific for GP IIb/IIIa and McAb XW-1 and SJ-9A4 are directed against CD9 antigen. All three McAbs were shown to elicit a Ca2+ rise in aequorin-loaded platelets. This rise was the sole result of Ca2+ influx in the case of Apt4 and XW-1 and of both Ca2+ influx and mobilization in the case of SJ-9A4. Platelet Ca2+ fluxes and aggregation induced by the three McAbs were inhibited by an anti-GP IIb/IIIa McAb HIP8. The Ca2+ channel blocker vorapamil exerted a complete inhibitory effect on platelet Ca2+ fluxes and aggregation induced by Apt4, and had a partial effect on that induced by XW-1 and SJ-9A4. The ADP inhibitor CP/CPK had a partial inhibitory effect on platelet Ca2+ fluxes and aggregation induced by Apt4 and XW-1, and a smal effect on that induced by SJ-9A4. The effects of the three McAbs were inhibited partially by the calmodulin inhibitor EBB. The results indicate that platelet Ca2+ fluxes induced by these three McAbs depend on different pathways.
钙在血小板激活过程中起着核心作用。使用PIGA仪器记录了单克隆抗体（McAbs）诱导的水母发光蛋白负载的人血小板中的钙变化。单克隆抗体Apt4对糖蛋白IIb/IIIa具有特异性，单克隆抗体XW-1和SJ-9A4针对CD9抗原。所有这三种单克隆抗体均显示可引起水母发光蛋白负载的血小板中Ca2+升高。在Apt4和XW-1的情况下，这种升高是Ca2+内流的唯一结果，而在SJ-9A4的情况下，是Ca2+内流和动员两者的结果。三种单克隆抗体诱导的血小板Ca2+通量和聚集受到抗糖蛋白IIb/IIIa单克隆抗体HIP8的抑制。钙通道阻滞剂维拉帕米对Apt4诱导的血小板Ca2+通量和聚集发挥完全抑制作用，对XW-1和SJ-9A4诱导的作用有部分影响。ADP抑制剂CP/CPK对Apt4和XW-1诱导的血小板Ca2+通量和聚集有部分抑制作用，对SJ-9A4诱导的作用有轻微影响。钙调蛋白抑制剂EBB对这三种单克隆抗体的作用有部分抑制作用。结果表明，这三种单克隆抗体诱导的血小板Ca2+通量取决于不同的途径。
