Ca2+ mobilization in blood platelets as visualized by chlortetracycline fluorescence.
Ca2+ mobilization in blood platelets as visualized by chlortetracycline fluorescence.
复制标题
通过金霉素荧光观察血小板中的 Ca2 动员。
DOI：
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发表时间：
1981
影响因子：
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通讯作者：
G. L. Le Breton
中科院分区：
文献类型：
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作者：
N. E. Owen;G. L. Le Breton
使用荧光Ca 2+探针、金霉素和光子计数显微荧光分光光度计在完整的人血小板中测定细胞内Ca 2+的结合。低剂量肾上腺素、A23187或前列腺素内过氧化物类似物U46619诱导血小板内膜结合Ca 2+释放。当维拉帕米或乙二胺四乙酸（EDTA）阻断血小板跨膜Ca ~（2+）通量时，肾上腺素引起的Ca ~（2+）动员受到抑制，而A23187或U46619诱导的Ca ~（2+）释放无变化。当吲哚美辛被用来抑制环氧合酶活性，响应肾上腺素或U46619的Ca 2+动员被部分阻断，而响应A23187的Ca 2+释放没有改变。同时观察了血小板环磷酸腺苷（cAMP）与血小板内钙结合的关系。前列腺素E1或前列环素被发现显着升高cAMP以及增强血小板Ca 2+结合。通过使用RO 201724抑制磷酸二酯酶活性增强了这些作用。在10-60 pmoles cAmP/ml富血小板血浆范围内，cAMP与Ca ~（2+）结合呈线性关系。此外，前列腺素E1或前列环素刺激的cAMP增加降低了肾上腺素、A23187或U46619诱导血小板内Ca 2+动员的能力。
Binding of intracellular Ca2+ was measured in intact human blood platelets using the fluorescent Ca2+ probe, chlortetracycline, and a photon-counting microspectrofluorometer. Low doses of epinephrine, A23187, or prostaglandin endoperoxide analog U46619 induced a release of intraplatelet membrane-bound Ca2+. When platelet transmembrane Ca2+ flux was blocked by verapamil or ethylenediaminetetraacetic acid (EDTA), Ca2+ mobilization in response to epinephrine was inhibited, whereas A23187- or U46619-induced Ca2+ release was unchanged. When indomethacin was used to inhibit cyclo-oxygenase activity, Ca2+ mobilization in response to epinephrine or U46619 was partially blocked, whereas Ca2+ release in response to A23187 was unaltered. The relationship between platelet cyclic adenosine 3',5'-monophosphate (cAMP) and intraplatelet Ca2+ binding was also investigated. Prostaglandin E1 or prostacyclin was found to markedly elevate cAMP as well as enhance platelet Ca2+ binding. These effects were augmented by inhibition of phosphodiesterase activity using RO201724. The relationship between cAMP and Ca2+ binding was linear in the range of 10-60 pmoles cAmP/ml platelet-rich plasma. In addition the increase in cAMP stimulated by prostaglandin E1 or prostacyclin reduced the ability of epinephrine, A23187, or U46619 to induce intraplatelet Ca2+ mobilization.