FEBS Letters | |
Activation of sodium‐proton exchange is not a prerequisite for Ca2+ mobilization and aggregation in human platelets | |
Gárdos, George3  Hunyady, László1  Cragoe, Edward J.2  Sarkadi, Balázs3  Spät, András1  | |
[1] Department of Physiology, Semmelweis University of Medicine, Puskin u. 9, PO Box 259, H-1444 Budapest 8 Hungary;Merck Sharp & Dohme Research Laboratories, West Point, PA 19486, USA;National Institute of Haematology and Blood Transfusion, H-1113 Budapest, Hungary | |
关键词: Ca2+ signal; Na+/H+ exchange; Thrombin; Amiloride analogue; (Human platelet); [Ca2+]i; cytoplasmic free Ca2+ concentration; CBDMB; 5-(N-4-chlorobenzyl)-N-(2′; 4′-dimethyl)benzamil; DMB; N-(2′; 4′-dimethyl)benzamil; EIPA; 5-(N-ethyl-N-isopropyl)amiloride; InsP3; inositol 1; 4; 5-trisphosphate; DAG; 1; 2-diacylglycerol; | |
DOI : 10.1016/0014-5793(87)81133-X | |
学科分类:生物化学/生物物理 | |
来源: John Wiley & Sons Ltd. | |
【 摘 要 】
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.
【 授权许可】
Unknown
【 预 览 】
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