【摘要】 目的:研究PAF诱导P-选择素表达的细胞内信号机制。方法:置备人血小板悬液,用流式细胞术测定PAF诱导的P-选择素表达。结果:用依他酸2mmol·L^-1和BAPTA200μmol·L^-1分别阻断外钙内流和络合内钙,显著抑制PAF诱导的P-选择素表达[13.3±0.9)％;（16.8±1.9）％ vs PAF对照组（47.5±1.3）％,P<0.01]。用阿米洛利400μmol·L^-1抑制Na⁺/H⁺交换,Genistein 300μmol·L^-1抑制蛋白酪氨酸磷酸化也均可抑制PAF引起的P-选择素上调[（37.5±2.1）％;（29±4）％ vsPAF对照组（47.5±1.3）％,P<0.01)]。结论:蛋白酪氨酸磷酸化,细胞内钙动员及Na⁺/H⁺交换激活中介PAF诱导的血小板P-选择素表达。更多还原

【Abstract】 AIM: To study the intracellular signal transduction mechanisms of platelet activating factor (PAF)-induced platelet P-selectin expression. METHODS: Human blood platelets were used to test the effect of PAF-induced P-selectin expression using flow cytometry. RESULTS: PAF 20 nmol·L-1 elicited a moderate up-regulation of P-selectin expression [(47.5 ± 1.3) % vs control (3.8±0.9) %, P<0.01]. Pretreatment with egtazic acid (EGTA) 2 mmol · L-1 and 5, 5’-dimethyl-bis-(o-aminophenoxy) -ethane- N, N, N’, N’ -tetracetic acid (BAPTA) 200 μmol·L-1 to block Ca2 + influx or chelate the intracellular calcium, respectively, reduced P-selectin expression in response to PAF [(13.3±0.9) % and (16.8±1.9) % vs (47.5± 1.3) % of PAF group, P < 0.01]. Inhibition of Na+/H+ exchange with amiloride (Ami) 400 μmol· L-1 resulted in an inhibition of P-selectin expression [(37.5 ± 2.1) % vs (47.5±1.3) % of PAF group, P <0.01]. Genistein (Gen) 300 μmol·L-1 to inhibit protein tyrosine phosphorylation showed similar effect [(29±4) % vs (47.5 ± 1.3) % of PAF group, P< 0.01]. CONCLUSION: Multiple signal transduction pathways, including protein tyrosine phosphorylation, Na+/H+ exchange, and Ca2+ mobilization, mediated PAF-induced P-selectin expression.更多还原