【摘要】 目的：研究５ＨＴ对ＳＴＡ２血小板聚集和释放反应的影响及可能的分子机制．方法：以透光法，介质中ＡＴＰ含量及荧光图像法评价血小板变形，聚集反应和［Ｃａ２］ｉ水平．结果：（１）５ＨＴ预处理可消除ＳＴＡ２的血小板变形，ＳＴＡ２０３μｍｏｌ·Ｌ－１的聚集增强，ｌ－３μｍｏｌ·Ｌ－１的聚集不变，释放反应抑制．（２）５ＨＴ预处理增加ＳＴＡ２０３μｍｏｌ·Ｌ－１的［Ｃａ２＋］ｉ，降低３μｍｏｌ·Ｌ－１的［Ｃａ２＋］ｉ降低．（３）延长加入５ＨＴ和ＳＴＡ２的间隔，ＳＴＡ２０３μｍｏｌ·Ｌ－１的聚集增强，３μｍｏｌ·Ｌ－１的聚集不变，释放反应抑制．结论：５ＨＴ对ＳＴＡ２介导的聚集和释放反应有双重影响．对ＳＴＡ２［Ｃａ２＋］ｉ的调节可能是上述反应的分子机制．更多还原

【Abstract】 1 Project Supported by National Postdoctoral Research Foundation (1993-1995). 2 Phn 86 451 667 1354. Fax 86 451 232 7091. E mail liby@ems.hrbmu.edu Abstract AIM: To study the effects of 5 hydroxytryptamine (5 HT) on stable analogue of thromboxane A 2 (STA 2) induced platelet shape, aggregation, and release reaction. METHODS: Platelet shape change and aggregation were quantified by the light transmission through platelet rich plasma (PRP). Release reaction was evaluated by the amount of ATP in the medium and cytosolic free Ca 2+ was measured by fluorescent imaging. RESULTS: (1) STA 2 0 3-3 μmol·L -1 induced shape change followed by aggregation. When STA 2 1 or 3 μmol·L -1 was added to PRP, the release reaction was occurred. Pretreatment of PRP with 5 HT 3 μmol·L -1 , the shape change by STA 2 was abolished and the aggregation by STA 2 0 3 μmol·L -1 was enhanced ( P <0 01), STA 2 1 or 3 μmol·L -1 induced aggregation was not affected, but the release reaction was partially suppressed ( P <0 01). (2) STA 2 0 3 μmol·L -1 induced [Ca 2+ ] i elevation was further increased by 5 HT pretreatment, but the [Ca 2+ ] i mobilizations by STA 2 3 μmol·L -1 was decreased by 5 HT, especially the peak level. (3) The aggregation without release reaction was increased from 3.4±2 1 to 25 6±1 8 % ( P <0 01) with 10 s interval and the enhancement was declined with the prolongation of the intervals. The aggregation with release reaction was not affected by changing the intervals, but the release reaction was decreased in the same treatment. CONCLUSION: The dual effects of 5 HT on STA 2 induced aggregation and release reaction and the molecular mechanism of this effect was probably through the regulative action of 5 HT on [Ca 2+ ] i mobilization by STA 2.更多还原