SJAMP对血小板胞内游离钙水平的影响

Effect of SJAMP on Platelet Cytosolic Free Ca^(2+)

目的：探讨Ca2+在SJAMP诱导血小板聚集中的作用。方法：以Fura-2为钙荧光探针，应用双波长法测定了SJAMP对血小板胞内游离钙水平的影响。结果：发现SJAMP在100μg／ml时对血小板胞浆游离钙的影响最为显著，可使正常人血小板胞内钙水平从71．30±7.66nmol／L升至93．96±10．24nmol/L（n＝10），在胞外存在1mmol／LCa2+时，SJAMP引起胞内游离钙升高幅度更大．可达116．72±10．66nmol／L（n=10）。另一方面，SJAMP对血小板胞内游离钙的影响，与其它诱导剂相比，其升高幅度较小且时限较长，同时如果血小板预先与环氧化酶抑制剂孵育．则SJAMP对血小板胞内钙的升高作用明显受抑。结论：推测SJAMP对血小板胞内钙的影响可能是一花生四烯酸及其代谢物有关的过程。

Using the method of dual-wavelength measurement of platelet (Ca2+)iand Fura-2 as the Ca2+ fluorophore probe, we measured the effect of Acidic Mu-copolysaccharide from Sticopus Japonicus Selenka (SJAMP) on platelet [Ca2-] i.The results showed that the most significant increase in plate1ets [Ca2+)i was seenwhen the concentration of SJAMP was 100 μg/ml and the elevation of normalplatelet [Ca2 +]i was 93. 96±10. 24 nmol/L, (n = 1O). In the presence of extracellular Ca2+ (1 mmol/L),the magnitude of platelets [Ca2+]i could reach 116. 72±10. 66nmol/I, (n=10). On the other hand,the magnitude of increased platelets [Ca2- ]ireaching the highest level was longer when compared with other platelet aggregationagents. In the mean time.if platelets was first incubated with cyclo-oxygenase inhibitor, the rise of (Ca2+]i evoked by SJAMP was inhibited. The results indlcatedthat the mechanism of the rise of [Ca2+]i induced by SJAMP might be dependentupon the generation of prostaglandin endperoxides and/or TXA2