کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
2201549 1100025 2010 9 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Impaired Na+-dependent glutamate uptake in platelets during depolarization of their plasma membrane
موضوعات مرتبط
علوم زیستی و بیوفناوری بیوشیمی، ژنتیک و زیست شناسی مولکولی بیولوژی سلول
پیش نمایش صفحه اول مقاله
Impaired Na+-dependent glutamate uptake in platelets during depolarization of their plasma membrane
چکیده انگلیسی

Blood platelets contain neuronal Na+-dependent glutamate transporters and are able to accomplish glutamate uptake. Applying high-KCl, we have demonstrated dose-dependent depolarization of the plasma membrane of rabbit platelets that was registered as an increase in the fluorescence of the potential-sensitive fluorescent dye rhodamine 6G. The initial velocity of L-[14C]glutamate uptake (10 μM) in platelets was decreased by 20% during 35 mM KCl-evoked depolarization and consisted of 1.2 ± 0.09 pmol × min−1 × mg−1 protein in control and 0.96 ± 0.08 pmol × min−1 × mg−1 protein during depolarization. Confocal laser scanning microscopy and flow cytometry revealed that these changes in glutamate uptake were not a result of platelet aggregation/activation. Also, addition of high-KCl did not change acidification of platelet secretory granules that was found with pH-sensitive fluorescent dye acridine orange, thereby showing that changes in their proton gradient could not cause glutamate uptake alteration. This malfunction of glutamate transporters has to take place under: (i) the conditions of pseudohyperkalemia or hyperkalemia, i.e. activation and clotting of platelets, haemolysis, leucocytosis, acute renal failure, hypofunction of adrenal cortex, lack of aldosterone, stroke, trauma and (ii) depolarization of the plasma membrane of platelets during their activation by ADP, thrombin, platelet-activating factor. Weak glutamate uptake might have considerable consequences for platelets per se (and thus for haemostatic system) and glutamate homeostasis in the CNS.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Neurochemistry International - Volume 56, Issue 5, April 2010, Pages 711–719
نویسندگان
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