کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
2536900 1559172 2006 10 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Paradoxical nifedipine facilitation of 45Ca uptake into rat hippocampal synaptosomes
موضوعات مرتبط
علوم زیستی و بیوفناوری علم عصب شناسی علوم اعصاب سلولی و مولکولی
پیش نمایش صفحه اول مقاله
Paradoxical nifedipine facilitation of 45Ca uptake into rat hippocampal synaptosomes
چکیده انگلیسی
Nifedipine has a high incidence of neurologic adverse reactions as compared with other dihydropyridine Cav1 (L-type) channel blockers used for treating cardiovascular diseases. The mechanism mediating neuronal excitation by nifedipine is still in debate. Nifedipine caused a dual role on veratridine-induced 45Ca uptake by rat hippocampal synaptosomes. In the nanomolar range (0.001-0.3 μM), nifedipine decreased 45Ca uptake in a cadmium-sensitive manner. In contrast with nitrendipine (0.001-10 μM), nifedipine consistently facilitated 45Ca accumulation when used in low micromolar concentrations (0.3-10 μM). The cadmium-insensitive nifedipine facilitation became less evident upon increasing veratridine concentration from 5 to 20 μM and was not detected when the synaptosomes where depolarised with 30 mM KCl. Na+ substitution by N-methyl-d-glucamine (132 mM) or blockade of Na+ currents with tetrodotoxin (1 μM) both prevented nifedipine excitation. The Na+/Ca2+-exchanger inhibitor, KB-R7943 (3-50 μM), did not reproduce nifedipine actions. Data suggest that tetrodotoxin-sensitive Na+ channels may operate paradoxical nifedipine facilitation of 45Ca uptake by rat hippocampal synaptosomes.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: European Journal of Pharmacology - Volume 544, Issues 1–3, 21 August 2006, Pages 39-48
نویسندگان
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