کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
2517001 1118915 2018 8 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Effects of clonidine and other imidazole-receptor binding agents on second messenger systems and calcium influx in bovine adrenal chromaffin cells
ترجمه فارسی عنوان
اثرات کلونیدین و دیگر گیرنده های گیرنده ایمیدازول بر سیستم های پیام رسان دوم و نفوذ کلسیم در سلول های کروافافی سلول های غده بالغ
موضوعات مرتبط
علوم پزشکی و سلامت داروسازی، سم شناسی و علوم دارویی داروشناسی
چکیده انگلیسی
Clonidine and related imidazoline compounds bind to α2-adrenergic as well as to newly described non-adrenergic imidazole/imidazoline receptors in brain and peripheral tissues. The present study was undertaken to identify the signal transduction mechanism coupled to this new class of receptors (imidazole receptors) using bovine adrenal chromaffin cells. Clonidine did not modify the basal or forskolin-stimulated production of cyclic AMP (cAMP), suggesting the absence of functionally active α2-adrenergic receptors in adrenal chromaffin cells. Clonidine also failed to modify the basal and GTPγS- or carbachol-stimulated increase in phosphoinositide hydrolysis. However, clonidine increased significantly the production of cyclic GMP (cGMP) as well as the uptake of 45Ca2+. The cGMP response to clonidine was slower (peak at 15 min) and smaller (only about 50% over control) than the response to acetylcholine and was not shared by other agents that bind to imidazole receptors. In contrast, all agents that bind to imidazole receptors increased the influx of 45Ca2+ into chromaffin cells. It is concluded that (a)α2-adrenergic and imidazole receptors are functionally distinct and linked to different signal transduction mechanisms; (b) the classical G-protein coupled soluble second messenger systems are not coupled to imidazole receptors; (c) clonidine may increase cGMP by a non-receptor-mediated intracellular action; and (d) imidazole receptors may regulate intracellular calcium levels through an ion regulating system that may be different from calcium channels.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Biochemical Pharmacology - Volume 42, Issue 10, 24 October 1991, Pages 2011-2018
نویسندگان
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