ACTIVATION OF SODIUM-PROTON EXCHANGE IS NOT A PREREQUISITE FOR CA-2+ MOBILIZATION AND AGGREGATION IN HUMAN-PLATELETS
ACTIVATION OF SODIUM-PROTON EXCHANGE IS NOT A PREREQUISITE FOR CA-2+ MOBILIZATION AND AGGREGATION IN HUMAN-PLATELETS
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DOI：
10.1016/0014-5793(87)81133-x
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发表时间：
1987-12-10
期刊：
影响因子：
3.5
通讯作者：
GARDOS, G
中科院分区：
文献类型：
--
作者：
HUNYADY, L;SARKADI, B;GARDOS, G
最近已经提出[（1987）Nature 325，456-458;（1987）FEBS Lett. 212，123-126]，Na+/H+交换的活化是血小板聚集和Ca 2+信号发展的先决条件。作为Na+/H+交换途径作用的直接证据，提供了Na+/H+交换的特异性抑制剂EIPA对Ca 2+信号的抑制。在这里，我们证明了低浓度的EIPA（低于1 μM）完全阻断Na+/H+交换，而EIPA仅在浓度大于1 μM的100倍时抑制聚集或Ca 2+动员。此外，另一种阿米洛利类似物CBDMB主要作用于Na+/Ca 2+交换，不影响血小板中的Na+/H+交换，但阻断聚集和Ca 2+动员。我们的结论是，虽然Na+/H+交换在血小板功能中具有重要作用，但它不是Ca 2+信号和聚集发展的先决条件。
Recently it has been suggested [(1987) Nature 325, 456–458; (1987) FEBS Lett. 212, 123–126] that the activation of Na+/H+exchange is a prerequisite for platelet aggregation and the development of the Ca2+signal. As direct evidence for the role of the Na+/H+-exchange pathway the inhibition of the Ca2+signal by EIPA, a specific inhibitor of Na+/H+exchange, was offered. Here we demonstrate that low concentrations of EIPA (below 1 μM) completely block Na+/H+exchange while EIPA inhibits aggregation or Ca2+mobilization only in concentrations 100-times greater than 1 μM. Moreover, another amiloride analogue, CBDMB, developed to act predominantly on Na+/Ca2+exchange, does not affect Na+/H+exchange in platelets but blocks aggregation and Ca2+mobilization. We conclude that while Na+/H+exchange has a fundamental role in platelet functions it is not prerequisite for the development of Ca2+signal and aggregation.