کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
2531975 1558958 2014 8 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Extracellular calcium modulates the inhibitory effect of 4-aminopyridine on Kv current in vascular smooth muscle cells
ترجمه فارسی عنوان
کلسیم خارج سلولی مولکول اثر مهاری 4-آمینوپیریدین بر جریان کروم در سلول های عضله صاف عروقی
موضوعات مرتبط
علوم زیستی و بیوفناوری علم عصب شناسی علوم اعصاب سلولی و مولکولی
چکیده انگلیسی

4-Aminopyridine is widely used as a Kv channel blocker. However, its mechanism of action is still a matter of debate. Extracellular calcium as well as 4-aminopyridine have been reported to interact with the activation kinetics of particular Kv channels. The objective of the present study was to investigate whether extracellular calcium could modulate the inhibition of Kv current by 4-aminopyridine in vascular myocytes. Kv current was recorded by using whole-cell patch-clamp in freshly isolated smooth muscle cells from rat mesenteric artery. Macroscopic properties of Kv current were not affected by change in extracellular calcium from 0 to 2 mM. During a 10 s depolarizing pulse, 4-aminopyridine inhibited the peak current without affecting the end-pulse current. The concentration–effect curve of 4-aminopyridine was shifted to the left in the presence of 2 mM calcium compared to 0 calcium. After 4-aminopyridine washout, current recovery from block was slower in the presence than in the absence of calcium. Inhibition of Kv current by 4-aminopyridine (0.5 mM) and the Kv2 blocker stromatoxin (50 nM) was additive and stromatoxin did not alter the potentiation of 4-aminopyridine effect by extracellular calcium. These results showed that extracellular calcium modulated the inhibitory potency of 4-aminopyridine on Kv current in vascular myocytes. The component of Kv current that was inhibited by 4-aminopyridine in a calcium-sensitive manner was distinct from Kv2 current.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: European Journal of Pharmacology - Volume 723, 15 January 2014, Pages 116–123
نویسندگان
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