Huang Xi-lian, Chen Fang-ping, Du Jian-wei, Peng Min-yuan, Fu Bin, Xie Qin-zhi, He Shi-lin
Department of Hematology, Xiangya Hospital, Central Southern University, Changsha, China.
Zhonghua Xue Ye Xue Za Zhi. 2005 Sep;26(9):525-8.
To explore whether normal platelet contains tissue factor (TF), and the significance of platelet-associated TF (PATF).
Platelets were isolated by Sepharose 2B gel column. ELISA was used to detect the TF content in the lysates of washed platelets. Procoagulant activity of PATF was measured by one stage clotting time assay. The mRNA of TF was detected by reverse transcription polymerase chain reaction (RT-PCR).
A certain amount of TF antigen (16.37 +/- 6.39) ng/L was detected in the washed-platelet lysates. Upon activation by collagen, platelets released TF and caused a marked increase in TF level in plasma (P <0.05). Resting platelets had no TF procoagulant activity, while procoagulant activity of platelets activated by collagen increased significantly, which could be blocked by TF McAb and poor VII plasma. TF mRNA could not be detected in washed platelets. TF content in platelets from patients with coronary heart disease was significantly higher than that from normal controls (P < 0.05). Resting platelets from the patients showed a higher procoagulant activity, which could be inhibited by TF McAb.
Platelets contain TF and the latter released by activated platelet was functionally active. Platelet itself might not synthesize TF. Protein content and procoagulant activity of PATF in patients with coronary heart disease were higher than that in controls. All these indicate that platelet may be involved in coagulation and thrombosis by releasing TF.
探讨正常血小板是否含有组织因子（TF）以及血小板相关组织因子（PATF）的意义。
通过琼脂糖2B凝胶柱分离血小板。采用酶联免疫吸附测定法（ELISA）检测洗涤后血小板裂解物中的TF含量。通过一期凝血时间测定法测量PATF的促凝活性。采用逆转录聚合酶链反应（RT-PCR）检测TF的信使核糖核酸（mRNA）。
在洗涤后血小板裂解物中检测到一定量的TF抗原（16.37±6.39）ng/L。经胶原激活后，血小板释放TF并导致血浆中TF水平显著升高（P<0.05）。静息血小板无TF促凝活性，而经胶原激活的血小板促凝活性显著增加，且可被TF单克隆抗体（McAb）和缺乏因子VII的血浆阻断。在洗涤后的血小板中未检测到TF mRNA。冠心病患者血小板中的TF含量显著高于正常对照组（P<0.05）。患者的静息血小板表现出较高的促凝活性，且可被TF McAb抑制。
血小板含有TF，激活的血小板释放的TF具有功能活性。血小板自身可能不合成TF。冠心病患者PATF的蛋白含量和促凝活性高于对照组。所有这些表明血小板可能通过释放TF参与凝血和血栓形成。
