应用Fura-2/AM荧光双波长法研究抑肽酶对血小板活化的保护作用

Protective mechanism of aprotinin in platelet activation by Fura-2/AM dual-wavelength method

目的 探讨抑肽酶对血小板活化的保护机制。方法 用钙荧光指示剂Fura 2 AM负载人洗涤血小板 ,用荧光双波长分光光度计比值法测定静息血小板胞浆游离钙浓度 ( [Ca2 + ] i)及凝血酶、抑肽酶对 [Ca2 + ] i 的影响。结果 在生理胞外Ca2 + 浓度时 ,正常人血小板 [Ca2 + ] i 静息水平为 ( 15 1 840± 2 8 719)nmol L ,凝血酶可引起血小板 [Ca2 + ] i 的明显增加(P <0 0 1) ,抑肽酶呈剂量依赖性地抑制由凝血酶引起的 [Ca2 + ] i 的增加 (P <0 0 1)。结论 抑肽酶的保护血小板机制与其抑制血小板内 [Ca2 + ] i

Objective To study the possible mechanisms of aprotinin in the protection of platelets. Methods Cytosolic free calcium concentration ([Ca 2+ ]i) was determined in calcium fluorescent indicator Fura 2/AM loaded washed human platelets by using dual wavelength spectrofluorophotometer. The mean value of resting [Ca 2+ ]i and the changes of [Ca 2+ ]i response to thrombin and aprotinin were observed. Results In the presence of extracellular Ca 2+ at the dose of 1 mmol/L, the resting level of [Ca 2+ ]i in platelets of human was (151.840±28.719) nmol/L. Thrombin stimulated the rise in [Ca 2+ ]i in the presence of Ca 2+ at the dose of 1 mmol/L, and the effects were inhibited by aprotinin in a concentration dependent manner ( P <0.01). Conclusion Aprotinin is an anti platelet agent and may exert its action through inhibiting the [Ca 2+ ]i mobilization in platelets.