目的和方法：用花生四烯酸（ＡＡ）诱导正常人（ｎ＝１２）富血小板血浆（ＰＲＰ）血小板活化。结果：ＡＡ组、消炎痛＋ＡＡ组及对照组血浆１１－去氢－血栓烷Ｂ２（ＤＨ－ＴＸＢ２）浓度分别为：（５１±２５、５．０±２．８及５４±３２）ｎｇ／Ｌ，三组之间无显著差别；但ＡＡ组ＴＸＢ２与Ｐ－选择素浓度均较对照组显著升高（Ｐ＜００１），消炎痛对两者的升高有几乎完全的抑制作用。２０例急性期脑梗塞患者血浆ＤＨ－ＴＸＢ２浓度（１０８～５５０ｎｇ／Ｌ）远高于对照组（１０～９３ｎｇ／Ｌ），无重叠，但两组之间ＴＸＢ２与Ｐ－选择素浓度均有５０％左右重叠。另６例患者服用９００ｍｇ阿司匹林后血浆ＤＨ－ＴＸＢ２下降４３％（Ｐ＜００１），但服药前后ＴＸＢ２及Ｐ选择素浓度无显著改变。结论：ＤＨ－ＴＸＢ２作为ＴＸＢ２的体内主要酶代谢产物，是反映体内血小板活化的一个较好的指标 PURPOSE AND METHODS: Arachidonic acid (AA) was used to induce platelet activation in normal human (n = 12) platelet-rich plasma (PRP). Results: The concentrations of 11-dehydro-thromboxane B2 (DH-TXB2) in AA group, indomethacin + AA group and control group were (51 ± 25, 5.0 ± 2.8 and 54 ± 32) ng / L, there was no significant difference among the three groups. However, the concentrations of TXB2 and P-selectin in AA group were significantly higher than those in control group (P <001) There is almost complete inhibition. The plasma levels of DH-TXB2 in 20 patients with acute cerebral infarction (108 ~ 550 ng / L) were much higher than those in the control group (10 ~ 93 ng / L) P-selectin concentrations are about 50% overlap. In the other 6 patients, the plasma DH-TXB2 decreased by 43% (P <001) after taking 900 mg of aspirin, but the TXB2 and P-selectin concentrations did not change significantly before and after taking the drug. Conclusion: DH-TXB2, as the major enzyme metabolite of TXB2, is a good indicator of platelet activation in vivo