老鹳草素对血小板聚集和血小板-中性粒细胞之间相互作用的影响(英文)

Effects of Geraniin on Platelet Aggregation and Interactions between Platelets and Neutrophils

目的研究老鹳草素抗血小板聚集作用及其对血小板与中性粒细胞之间相互作用的影响.方法采用Born方法观测老鹳草素在体内和体外对家兔血小板聚集功能的影响,运用玫瑰花结实验测定血小板与中性粒细胞的黏附反应,以Fura-2-AM为荧光指示剂,检测老鹳草素对激活的血小板内钙水平的影响.结果老鹳草素在体外呈浓度依赖性明显抑制花生四烯酸(AA)、腺苷二磷酸(ADP)及血小板活化因子(PAF)诱导的血小板聚集功能.其半数抑制浓度(IC50)分别为2.4、0.4和1.1μmol/L;5 mg/kg的老鹳草素灌胃亦明显抑制AA、ADP和PAF诱导的血小板聚集;老鹳草素显著降低洗涤血小板内钙离子浓度、减少细胞外钙内流及内钙释放,其IC50分别为71.9、84.9、62.9μmol/L.老鹳草素明显阻抑凝血酶激活的血小板与中性粒细胞之间的黏附作用,并抑制肉豆蔻佛波醇(fMLP)激活的中性粒细胞上清液诱导的血小板聚集功能,其IC50分别为3.2和10.2μmol/L.结论老鹳草素明显抑制血小板聚集功能,降低血小板内钙水平,同时阻抑血小板与中性粒细胞之间的相互作用.

Objective To investigate the effects of geraniin on platelet aggregation and platelet-neutrophil interactions.Methods Platelet aggregation,in vitro and ex vivo,was determined by use of Born's method,and the binding of thrombin-stimulated platelets to neutrophils was observed based on the rosette assay.Intracellular calcium concentration of platelets was measured by using Fura-2-AM.Results Geraniin in vitro significantly inhibited arachidonic acid(AA)-,adenosine diphosphate(ADP)-,or platelet activating factor(PAF)-induced platelet aggregation,in a concentration-dependent manner.The medium inhibitory concentrations(IC50)were 2.4,0.4 and 1.1 μmol/L,respectively.Intragastric geraniin at 5 mg/kg markedly suppressed platelet aggregation induced by AA,ADP,or PAF.Geraniin decreased the total rise of i,Ca2+ release,and Ca2+ influx,in a concentration-dependant manner.The IC50 values were 71.9,84.9,and 62.9 μmol/L,respectively.Geraniin decreased the binding of thrombin-stimulated platelets to neutrophils,and significantly inhibited washed platelet aggregation stimulated by fMLP-activated neutrophils.The IC50 values were 3.2 and 10.2 μmol/L,respectively.Conclusion It is suggested that geraniin inhibited platelet aggregation in vitro and ex vivo,decreased the calcium mobilization of platelets,and suppressed the interactions between platelets and neutrophils.