Lee H R, Roeske W R, Yamamura H I
Life Sci. 1984 Aug 13;35(7):721-32. doi: 10.1016/0024-3205(84)90340-0.
The binding properties of the 1,4-dihydropyridine calcium channel antagonist, 3HPN 200-110, were studied in rat cerebral cortical and cardiac homogenates (37 degrees C, Krebs phosphate buffer). Specific binding of 3HPN 200-110 was saturable, reversible, and of high affinity (Kd values are 35 and 64 pM for the cerebral cortex and heart, respectively). In parallel studies with 3HPN 200-110, the dissociation constant of [3H]nitrendipine was 10-12 times higher. Substituted dihydropyridine calcium channel antagonists and agonists competitively inhibited specific 3HPN 200-110 binding, but d-cis diltiazem enhanced and verapamil incompletely inhibited 3HPN 200-110 binding in both the cerebral cortex and the heart. The effects of diltiazem and verapamil on 3HPN 200-110 binding were due mainly to alterations in the dissociation constant (Kd), without alterations in the binding density (Bmax). The new 3HPN 200-110 receptor binding assay is remarkable for its low degree of nonspecific binding as compared to [3H]nitrendipine at physiological temperatures. 3HPN 200-110 is a useful ligand for the further analysis of the dihydropyridine binding sites associated with calcium channels.
在大鼠大脑皮层和心脏匀浆（37℃，磷酸 Krebs 缓冲液）中研究了 1,4 - 二氢吡啶类钙通道拮抗剂³HPN 200 - 110 的结合特性。³HPN 200 - 110 的特异性结合是可饱和的、可逆的且具有高亲和力（大脑皮层和心脏的 Kd 值分别为 35 和 64 pM）。在与³HPN 200 - 110 的平行研究中，[³H]尼群地平的解离常数高 10 - 12 倍。取代的二氢吡啶类钙通道拮抗剂和激动剂竞争性抑制³HPN 200 - 110 的特异性结合，但 d - 顺式地尔硫䓬增强了³HPN 200 - 110 的结合，维拉帕米在大脑皮层和心脏中均未完全抑制³HPN 200 - 110 的结合。地尔硫䓬和维拉帕米对³HPN 200 - 110 结合的影响主要是由于解离常数（Kd）的改变，而结合密度（Bmax）未改变。与生理温度下的[³H]尼群地平相比，新的³HPN 200 - 110 受体结合测定法的非特异性结合程度较低。³HPN 200 - 110 是用于进一步分析与钙通道相关的二氢吡啶结合位点的有用配体。
