作者:S.-R. Kim、J.-Y. Lee、M.-Y. Lee、S.-M. Chung、O.-N. Bae、J.-H. Chung
DOI:10.1093/toxsci/62.1.176
日期:2001.7.1
Various anti-platelet drugs, including quinones, are being investigated as potential treatments for cardiovascular disease because of their ability to prevent excessive platelet aggregation. In the present investigation 3 naphthoquinones (2,3-dimethoxy-1,4-naphthoquinone [DMNQ], menadione, and 1,4-naphthoquinone [4-NQ]) were compared for their abilities to inhibit platelet aggregation, deplete glutathione (GSH) and protein thiols, and cause cytotoxicity. Platelet-rich plasma, isolated from Sprague-Dawley rats, was used for all experiments. The relative potency of the 3 quinones to inhibit platelet aggregation, deplete intracellular GSH and protein thiols, and cause cytotoxicity was 1,4-NQ > menadione >> DMNQ. Experiments using 2 thiol-modifying agents, dithiothreitol (DTT) and 1-chloro-2,4-dintrobenzene (CDNB), confirmed the key roles for GSH in quinone-induced platelet anti-aggregation and for protein thiols in quinone-induced cytotoxicity. Furthermore, the anti-aggregative effects of a group of 12 additional quinone derivatives were positively correlated with their ability to cause platelet cytotoxicity. Quinones that had a weak anti-aggregative effect did not induce cytotoxicity (measured as LDH leakage), whereas quinones that had a potent anti-aggregative effect resulted in significant LDH leakage (84–96%). In one instance, however, p-chloranil demonstrated a potent anti-aggregative effect, but did not induce significant LDH leakage. This can be explained by the inability of p-chloranil to deplete protein thiols, even though intracellular GSH levels decreased rapidly. These results suggest that quinones that deplete GSH in platelets demonstrate a marked anti-aggregative effect. If this anti-aggregative effect is subsequently followed by depletion of protein thiols, cytotoxicity results.
多种抗血小板药物,包括醌类,正在被研究作为心血管疾病的潜在治疗方法,因为它们能够防止血小板过度聚集。在本研究中,比较了三种萘醌(2,3-二甲氧基-1,4-萘醌[DMNQ]、甲萘醌和1,4-萘醌[4-NQ])抑制血小板聚集、耗竭谷胱甘肽(GSH)和蛋白硫醇以及引起细胞毒性的能力。所有实验均使用从Sprague-Dawley大鼠中分离的富含血小板的血浆进行。三种醌抑制血小板聚集、耗竭细胞内GSH和蛋白硫醇以及引起细胞毒性的相对效力为1,4-NQ > 甲萘醌 >> DMNQ。使用两种硫醇修饰剂,二硫苏糖醇(DTT)和对氯间二硝基苯(CDNB)的实验证实了GSH在醌诱导的血小板抗聚集中的关键作用以及蛋白硫醇在醌诱导的细胞毒性中的作用。此外,一组12种额外醌衍生物的抗聚集作用与其引起血小板细胞毒性的能力呈正相关。具有弱抗聚集作用的醌不会诱发细胞毒性(以LDH泄漏衡量),而具有强抗聚集作用的醌则会导致显著的LDH泄漏(84-96%)。然而,在一种情况下,p-氯醌表现出强大的抗聚集作用,但没有诱导显著的LDH泄漏。这可以通过p-氯醌不能耗竭蛋白硫醇来解释,尽管细胞内GSH水平迅速下降。这些结果表明,耗竭血小板中GSH的醌表现出显著的抗聚集作用。如果这种抗聚集作用随后伴随着蛋白硫醇的耗竭,则会导致细胞毒性。