体外循环对P选择素及血栓调节蛋白影响的研究

The relation between P-selection and thrombomodulin during extracorporeal circulation

目的 探讨体外循环对血小板活化及血管内皮细胞损伤的影响及其相互之间的关系。方法 对 7例风湿性心脏病患者在体外循环前、中、后 5个时点采血。用流式细胞仪检测血小板膜P选择素的表达率及荧光强度 ,同时用ELISA检测血浆中P选择素及血栓调节蛋白的含量。结果 血小板膜P选择素的表达率从体外循环中 15min开始上升 ,6 0min时达高峰 ,之后逐渐下降 ,术后 2 4h仍高于术前水平 ,各时点之间的差异具统计学意义 (P <0 0 1)。血浆P选择素和血栓调节蛋白浓度的变化规律与血小板膜P选择素阳性率基本类似。三者之间的Pearson相关系数均大于 0 85 (P <0 0 1) ,呈明显的正相关。而P选择素的荧光强度变化不明显 (P >0 0 1)。结论 随着体外循环时间的延长血小板活化增加 ,血管内皮细胞损伤加重 ,且两者之间互为因果。

Objective To explore the relation between platelet activation and damage of endothelial cells. Methods The blood samples were obtained through venous catheter from 7 patients undergoing elective cardiac operation for valvular replacement at five different time points during extracorporeal circulation and after extracorporeal circulation. The presence of in vitro platelet activation was assessed by using flow cytometry to detect the positive rate of P selection and the fluorescent density on platelet membrane and using ELISA to detemine the plasma levels of P selectin. ELISA was used to measure plasma level of thrombomodulin as the sign of the endothelial cell damage. Results The positive rate of P selection on platelet membrane and the plasma level of sP selectin and thrombomodulin significantly increased during extracorporeal circulation, with a peak at 1 hour after extracorporeal circulation beginning, and decreased after extracorporeal circulation. The correlation between each other was significant among these three parameters. The change of fluorescent density of P selection at different time points was tiny. Conclusion With the extracorporeal circulation longthening, platelet activation increases and the damage of the endothelial cells become more obvious. Platelet activation and the damage of the endothelial cells were affected reciprocally.