[3H]Verapamil binding sites in brain and skeletal muscle: regulation by calcium.
[3H]Verapamil binding sites in brain and skeletal muscle: regulation by calcium.
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[3H]维拉帕米在大脑和骨骼肌中的结合位点:钙的调节。
DOI:
10.1016/0014-2999(83)90655-6
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发表时间:
1983
影响因子:
5
通讯作者:
Snyder,SH
中科院分区:
文献类型:
--
作者:
Reynolds,IJ;Gould,RJ;Snyder,SH
Several different classes of calcium channel antagonist drugs ernst. Binding sites for the dihydropyridine calcium channel antagonists can be labeled with [3H] nitrendipine. While drugs of the verapamil and diltiazem classes do not act at the dlhydropyridine sites, these drugs influence [3H] nltrendipine binding at a common site, distinct from the nitrendipine site (Murphy et al., 1983). In an effort to study directly the sites where verapamil-like drugs act, we have explored the binding of [3H] verapamil to tissue membranes. Rat cerebral cortices or skeletal muscle were homogenized in 10-20 vols. of 50 mM HEPES (N-2-hydroxyethyl piperazine-N'-2-ethanesulfonxc acid), pH 7.4, containing 1-10 mM EDTA (ethylenedlamine-tetraacetlc acid). After centrifugtng at 50000× g for 10 nun the pellet was resuspended in EDTA buffer. After repeating this centrifugation two times, the membranes were resuspended in the absence of EDTA to a concentration of 5-10 mg/ml wet weight. Incubations were carried out at room temperature for 45 min in a volume of 0.5-1 ml, containing 3-5 mg tissue and 2 nM [3H] verapamil. Nonspecific binding was assessed in the presence of 3~ M methoxyverapamil (D-600). Incubations were stopped by rapid filtration over Schleicher and Schuell No. 32 glass fiber filters previously soaked in 0.1% polyethyleneimine. Membranes were washed with 5-10 ml ice-cold 50 mM HEPES (pH 7.4) and radioactivity retained by the filters was measured. Drug sources were:[3H] verapamil (75 C1/mmol) was obtained