人血小板密度亚群在聚集反应,ATP释放及细胞内游离钙浓度的异质性

摘要

To investigate thrombin (500 U· L-1 )-,gation, secretion of ATP and cytosolic-free calcium mobilization in density subpopulations of human washed platelets. METHODS: Using Percoll discontinuous gradient. RESULTS: The human platelets were separated into high density (HD), intermediate density (ID), and low density (LD)subpopulations, and their sizes were diminished with decreasing density ( r = 0.978, P ＜ 0.01 ).The magnitude of aggregations by thrombin, ADP,and 5-HT was more significant in HD platelets than that in LD platelets (P ＜ 0.01). The amount of secretion of ATP induced by thrombin and ADP in HD platelets was also much higher than that in LD platelets (P ＜ 0.01), except for 5-HT which did not cause the ensuring release reaction in any subpopulation of human platelets. Thrombin (1500 Uwas evaluated as well. Results showed that the restin g level of cytosolic-free calcium concentration ([Ca2+ ]i) was the same in all subpopulations,[Ca2+ ]i mobilization was entirely different, heightened with increasing density. CONCLUSION: The function of HD platelets was much stronger and more active than that of LD platelets in human.%研究人血小板密度亚群在聚集和释放反应及细胞内钙浓度的异质性.方法:Percoll间断梯度离心法.结果:正常人血小板分为高(HD),中(ID)和低(LD)密度三个亚群.血小板的大小随密度的降低而减小(r=0.978,P＜0.01).HD对凝血酶(Thr),ADP和血清素(5-HT)诱导的聚集反应明显强于LD(P＜0.01),ATP释放反应,除5-HT无ATP释放外,与聚集反应的结果一致.尽管细胞内游离钙([Ca2+]i)的静息水平各亚群相同,但Thr,ADP和5-HT的[Ca2+]i动员仍以HD最为明显.结论:人HD血小板的功能及活性均高于LD血小板.