Amorepacific CO R&D Center, Yongin 446-729, Republic of Korea.
Thromb Res. 2011 Jun;127(6):565-70. doi: 10.1016/j.thromres.2011.02.004. Epub 2011 Mar 21.
We evaluate the anti-platelet and anti-thrombotic effects of cilostazol using Multiplate® and PFA-100® in vitro and ex vivo with freshly isolated rat whole blood and in vivo venous and arterial thrombosis models in the same species, in an effort to assess the sensitivity of the whole blood aggregometer assays without potential issues of species differences. In vitro assay of anti-platelet effects of cilostazol against collagen-induced aggregation using Multiplate® produced a graded dose-dependent inhibition curve with IC50 value of 75.4 ± 2.4 μM while it showed a highly sensitive and all-or-none type inhibition response from 25 μM in PFA-100®. Interestingly, cilostazol manifested anti-thrombotic effects in vivo at much lower plasma concentrations than the effective concentrations measured in ex vivo or in vitro aggregation tests using PFA-100® or Multiplate®. In addition, the tail bleeding time measurement demonstrated that rats have lower sensitivity to the anti-platelet effects of cilostazol than mice. These results suggest that the detailed comparative evaluation of whole blood aggregometer assays with anti-thrombotic effects in vivo should be preceded before the application of these methods for the pharmacodynamic studies of anti-thrombotic agents.
我们使用 Multiplate® 和 PFA-100® 在体外和体内评估西洛他唑的抗血小板和抗血栓作用，分别使用新鲜分离的大鼠全血和同种动物的静脉和动脉血栓形成模型，并努力评估全血聚集仪测定的敏感性，而不考虑种属差异的潜在问题。使用 Multiplate® 评估西洛他唑对胶原诱导聚集的抗血小板作用的体外测定产生了一个分级剂量依赖性抑制曲线，IC50 值为 75.4 ± 2.4 μM，而在 PFA-100® 中则表现出高度敏感的全或无型抑制反应，从 25 μM 开始。有趣的是，西洛他唑在体内表现出抗血栓作用的血浆浓度远低于使用 PFA-100® 或 Multiplate® 的体外聚集试验测量的有效浓度。此外，尾巴出血时间测量表明，大鼠对西洛他唑的抗血小板作用的敏感性低于小鼠。这些结果表明，在将这些方法应用于抗血栓药物的药效学研究之前，应该先对全血聚集仪测定与体内抗血栓作用进行详细的比较评估。
