左旋精氨酸和西洛他唑对血小板体外激活的抑制作用

本实验旨在研究左旋精氨酸(L-arginine)和西洛他唑(cilostazol)在体外对血小板激活的抑制和功能保护作用,为可逆性血小板抑制剂在血小板保存中的应用提供依据。采用对血小板CD62p和PAC-1表达及凝血酶激活后再表达率的流式细胞分析(FCMs)、血小板聚集试验以及血小板凝血活性检测等手段,观察血小板激活、血小板功能状态。结果表明,体外处理后血小板CD62p和PAC-1表达率显著增加,西洛他唑和左旋精氨酸对这一过程CD62p和PAC-1表达有较强抑制作用,且随浓度增加而递增。西洛他唑可抑制凝血酶激活后CD62p和PAC-1的表达,左旋经氨酸仅抑制凝血酶激活后的PAC-1表达。左旋精氨酸和西洛他唑对3种诱导剂诱导的血小板聚集呈现不同程度的抑制作用,抑制作用随浓度递增。左旋精氨酸≥15mmol/L时,血小板聚集时间延长甚至不凝集。西洛他唑在浓度1-4mmol/L范围均延长血小板聚集时间。结论:5mmol/L和10mmol/L的左旋精氨酸均可抑制血小板体外处理过程的激活,且血小板的聚集和再表达功能不受影响,5mmol/L作用更佳。1mmol/L浓度西洛他唑抑制血小板体外激活,可保留血小板部分聚集活性和再表达能力。

Inhibition of L-Arginine and Cilostazol on Activation of Platelets In Vitro

The purpose of study was to investigate the effects of L-arginine and cilostazol on platelet-activation and aggregation reserve in vitro, so as to provide proof for selecting reversible activation-inhibitors for platelets lyophilization. Activation and function of platelets were investigated by using flow cytometry with the CD62p and PAC-1 expression and re-expression after being activated by thrombin, and by means of platelet aggregation reaction to thrombin, ADP and propyl gallate, as well as coagulation activity of platelets. The results showed that expression of CD62p and PAC-1 increased after being pretreated. Both L-arginie and cilostazol could inhibit CD62p and PAC-1 expression and related with their concentrations. Cilostazol had an intensive inhibition effect on expressions of CD62p and PAC-1 induced by thrombin, and the inhibition increased when concentration augmented. L-arginine had the same effects on PAC-1, but had no effects on CD62p. L-arginine and cilostazol inhibited aggregation induced by thrombin, ADP and propyl gallate, and the inhibitions were related directly with dosage. When L-arginine concentration was higher or equal to 15 mmol/L, or cilostazol concentration was in range of 1-4 mmol/L, the aggregation time were prolonged so much or even no aggregation. It is concluded that when L-Arginine concentration is 5 mmol/L and 10 mmol/L, platelet activation can be inhibited, but aggregation ability and characters keep intact. Concentration at 5 mmol/L may be the best. 1 mmol/L of cilostazol can inhibit activation in vitro and retain part of platelet ability of aggregation and reexpression.