Regulatory role of protein tyrosine phosphorylation in platelet activating factor-induced signal transduction in platelets  

Regulatory role of protein tyrosine phosphorylation in platelet activating factor induced signal transduction in platelets 1

作　　者：曾珊[1] 易富贤[1] 郭兆贵[1] 

机构地区：[1]湖南医科大学分子药理研究室

出　　处：《中国药理学报》1999年第2期157-161,共5页Acta Pharmacologica Sinica

摘　　要：目的：研究蛋白酪氨酸磷酸化（ＰＴＰ）在血小板激活因子（ＰＡＦ）诱导血小板信号传导中的作用．方法：用水洗兔血小板考查Ｇｅｎ抑制聚集及５羟色胺释放，Ｆｕｒａ２和ＢＣＥＣＦ负载测胞内钙及ｐＨ，特异性抗酪氨酸单抗及免疫印迹法检测ＰＴＰ．结果：Ｇｅｎ１００和２００μｍｏｌ·Ｌ－１分别抑制ＰＡＦ诱导的５羟色胺释放为２３７％±２０％及４１％±８％，对胞内钙增加和Ｎａ＋／Ｈ＋交换也有抑制作用．ＰＡＦ增加Ｍｒ为７００００，６００００，５００００，４２０００／４００００，３４０００的ＰＴＰ．Ｇｅｎ２００，４００μｍｏｌ·Ｌ－１明显抑制该效应．用Ｓｔａ２０ｎｍｏｌ·Ｌ－１，ＢＡＰＴＡ２００μｍｏｌ·Ｌ－１，依他酸２ｍｍｏｌ·Ｌ－１，分别阻断ＰＫＣ及胞内钙增加和内流，也减少ＰＴＰ形成．结论：ＰＴＰ参与ＰＡＦ诱导血小板信号传导途径，ＰＫＣ活化和胞内钙动员对ＰＴＰ有调节作用．AIM: To study the role of protein tyrosine phosphorylation (PTP) in platelet activating factor (PAF) induced platelet signal transduction cascade. METHODS: Washed rabbit platelets were used to test the inhibitory effect of genistein (Gen) on platelet aggregation and serotonin secretion. Intracellular Ca 2+ ([Ca 2+ ] i) and pH (pH i) were measured by a dual wavelength fluorophotometer with Fura 2 AM and BCECF AM. PTP was determined with a specific anti phosphotyrosine monoclonal antibody by Western blotting. RESULTS: Pretreatment with Gen (100 and 200 μmol·L -1 ) inhibited PAF (20 nmol·L -1 ) stimulated platelet serotonin release by 23 7 %±2 0 % and 41 %±8 %, re￣spec￣tive￣ly. Similar inhibitory effects of Gen were observed on PAF evoked increase of [Ca 2+ ] i and intracellular alkalization. PAF also elicited a pronounced increase in PTP of several bands with M r 70 000, 60 000, 50 000, 42 000/40 000, and 34 000 , which were suppressed markedly by Gen 200 and 400 μmol·L -1 . Pretreatment with staurosporine (Sta) 20 nmol·L -1 , BAPTA 200 μmol·L -1 , and egtazic acid 2 mmol·L -1 to inhibit PKC activation, [Ca 2+ ] i elevation, and Ca 2+ influx respectively, also showed an inhibitory effects on the formation of PTP. CONCLUSION: PTP is involved in multiple signal transduction pathways induced by PAF, on which PKC activation and calcium mobilization play a regulatory role.

关 键 词：血小板激活因子 PTP 酪氨酸 磷酸化 

分 类 号：R331.143[医药卫生—人体生理学]