Endothelin-3 reduces Ca(2+)-uptake and Ca2+ content of platelet internal stores.
Endothelin-3 reduces Ca(2+)-uptake and Ca2+ content of platelet internal stores.
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Endothelin-3 可减少 Ca(2) 摄取和血小板内部储存的 Ca2 含量。
DOI：
10.1006/bbrc.1995.1741
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发表时间：
1995
影响因子：
3.1
通讯作者：
Devynck,MA
中科院分区：
文献类型：
--
作者：
Astarie-Dequeker,C;Pernollet,MG;LeBreton,G;Devynck,MA
在刺激的血小板中，内皮素-3（ET-3）先前已被证明可减弱Ca 2+动员。使用钙指示剂金霉素，本研究表明，0.5 μM ET-3使A23187动员的Ca 2+池减少24%。1 μM以下的ET-3剂量依赖性地降低血小板膜泡摄取~（45）Ca ~（2+）的初始速率和稳态值（p<0.001）。此外，ET-3部分逆转半最大有效浓度的毒胡萝卜素和2，5-二-（叔丁基）-1，4-苯并氢醌，两个特异性抑制剂的肌/内质网Ca ~（2+）-ATP酶的抑制作用。这些结果表明，ET-3是功能耦合到致密管系统的Ca ~（2+）泵。基于这些发现，我们提出ET-3降低了致密小管系统中Ca 2+泵的活性，致密小管系统积累较少的Ca 2+，导致对激动剂响应的Ca 2+释放降低。
In stimulated platelets, endothelin-3 (ET-3) has been previously shown to attenuate Ca2+mobilization. Using the calcium indicator chlortetracycline, the present study demonstrates that 0.5 μM ET-3 produced a 24% reduction in the Ca2+pool mobilized by A23187. ET-3 up to 1 μM dose-dependently decreased the initial velocity and steady state value of45Ca2+-uptake into platelet membrane vesicules (p<0.001). In addition, ET-3 partially reversed the inhibitory effects of half maximally effective concentrations of thapsigargin and 2,5-di-(t-butyl)-1,4-benzohydroquinone, two specific inhibitors of the sarco/endoplasmic reticulum Ca2+-ATPases. These results suggest that ET-3 is functionally coupled to Ca2+-pumps of the dense tubular system. Based on these findings, we propose that ET-3 decreases the activity of Ca2+-pumps in the dense tubular system which accumulates less Ca2+, leading to lowered Ca2+release in response to agonists.