摘要
Aim L-Arginine· L-aspartate, a double salt, has been recently reported toinhibit platelet aggregation and thrombosis, but its action mechanism is not clear yet. This studywas conducted to investigate its effect on FITC-PAC-1, an anti-glycoprotein IIb/IIIa monoclonalantibody binding to activated platelets, and on correlative autacoid levels in plasma or inplatelets in order to explore its potential pathway of inhibiting platelet aggregation andthrombosis. Methods Monoclonal antibody binding to activated platelets was assayed by flowcytometry; NO was assessed by colorimetric method. cAMP, TXB_2 or 6-keto-PGF_(1α) levels wereassessed by radioimmunoassay. Results Gavaged 30 mg·kg^(-1) of L-arginine·L-aspartate increasedboth concentration of NO in plasma and 6-keto-PGF_(1) in incubated supernatant of aortic segment ofrats ex vivo (P < 0.05), but it did not influence cAMP content in platelets and the level of TXB_2or 6-keto-PGF_(1) in plasma of rats, whereas ASA significantly lowered TXB_2 or 6-keto-PGF_(1α) inplasma. Both 100 μmol-L^(-1) of L-arginine ·L-aspartate and ASA inhibited FITC-PAC-1 binding toactivated platelets in vitro. Conclusion The increase in NO and PGI_2 release from endo-thelialcells and consequent inhibition of platelet activation may contribute to the inhibition of plateletaggregation and thrombosis by L-arginine· L-aspartate; whereas arachidonic acid or cAMP metabolicpathway is not closely correlative with the studied effect.
目的 L -精氨酸·L门冬氨酸盐具有抑制血小板聚集和血栓形成的作用 ,本文观察它在体外对GPIIb IIIa单抗FITC PAC 1与洗涤家兔血小板结合的影响和体内给药对大鼠血小板活性物质的影响 ,以探讨其作用机制。方法 用流式细胞仪测定抗体与活化血小板的结合 ;用比色法测定血清NO浓度 ;用放免法测定cAMP ,TXA2 和PGI2 水平。结果 L -精氨酸·L门冬氨酸盐 3 0mg·kg- 1灌胃给药 ,可明显增加大鼠血浆NO浓度和大鼠主动脉段体外培养上清液中 6 keto PGF1α水平 ,但对血浆中TXB2 和 6 keto PGF1α水平和血小板内cAMP的含量无明显影响 ,而乙酰水杨酸则明显降低血清TXB2 和 6 keto PGF1α水平。L -精氨酸·L门冬氨酸盐 10 0 μmol·L- 1在体外可明显减少GPIIb IIIa单抗FITC PAC 1与血小板的结合。结论 L -精氨酸·L-门冬氨酸盐抑制血小板聚集和抗血栓形成的功效可能通过增加血管内皮细胞释放NO和PGI2 ,继而阻止血小板活化来介导 。
