Enhancement of ADP-induced aggregation by 5-HT in rabbit platelets  

作　　者：李柏岩[1,2] 白颖[1,2] 李文汉[1,2] 

机构地区：[1]哈尔滨医科大学药理教研室 [2]哈尔滨第一医院神经科

出　　处：《中国药理学报》1998年第1期58-62,共5页Acta Pharmacologica Sinica

摘　　要：目的：研究５ＨＴ对ＡＤＰ介导的血小板聚集反应的增强作用．方法：以透光法、图像法和受体结合法评价聚集反应、单细胞内钙和三磷酸肌醇的含量．结果：５ＨＴ（００３－３μｍｏｌ·Ｌ－１）浓度依赖性地引起ＰＲＰ的透光度降低（ＤＬＴ），电镜结果显示血小板变形的同时伴有颗粒中心化，无聚集和释放反应．Ｆｕｒａ２负载后，５ＨＴ升高［Ｃａ２＋］ｉ，９０秒达峰值，ＩＰ３一过性升高．ＡＤＰ同样引起ＤＬＴ，但可被５ＨＴ消除，呈浓度依赖性．ＡＤＰ的聚集反应和［Ｃａ２＋］ｉ动员则由于５ＨＴ预处理而升高．结论：５ＨＴ增强ＡＤＰ的聚集反应与５ＨＴ的细胞内钙动员及ＡＤＰ的外钙内流两者的叠加作用有关．AIM: To study the enhanced effects of 5 hydroxytryptamine (5 HT) on ADP induced aggregation. METHODS: Platelet aggregation was quantified by the light transmission, the cytosolic free calcium ([Ca 2+ ] i) was measured by digital fluorescent microscopy, and inositol 1,4,5 triphosphate (IP 3) was determined by receptor binding assay. RESULTS: In rabbit platelet rich plasma (PRP), 5 HT 0 03-3 μmol·L -1 induced a decrease in light transmission (DLT) in a concentration dependent manner with centralization of granules, as revealed by electron microscopy. The DLT was accompanied with neither platelet aggregation nor a release reaction. In single washed platelets loaded with Fura 2, 5 HT caused a concentration dependent elevation of [Ca 2+ ] i, and IP 3 level was also transiently increased in washed platelets at 15 s after stimulation by 5 HT. Adenosine diphosphate (ADP) also caused DLT transiently in PRP before its own aggregation without a release reaction. Pretreatment of PRP or washed platelets with 5 HT, the DLT by ADP was reduced concentration dependently and ADP induced aggregation and [Ca 2+ ] i mobilization were enhanced. CONCLUSION: The enhancement of ADP induced aggregation was attributed to the superimposition of the calcium release from the storage sites and calcium influx induced by ADP over the calcium release from the storage sites by 5 HT.

关 键 词：血清素 腺苷二磷酸 血小板聚集 

分 类 号：R973.1[医药卫生—药品] R963[医药卫生—药学]