Bellemann P, Ferry D, Lübbecke F, Glossman H
Arzneimittelforschung. 1981;31(12):2064-7.
The tritiated calcium antagonist 1,4-dihydro-2,6-dimethyl-4-(3-nitrophenyl)-3,5-pyridine carboxylic acid, 3-ethyl-5-methyl ester (nitrendipine, Bay e 5009), a potent analogue of nifedipine, binds in a reversible and saturable manner to partially purified guinea-pig heart membranes. The analyses of the equilibrium binding data with Scatchard plots is in accord with either negative cooperativity of binding or with the assumption of two classes of binding sites, where one site has an equilibrium dissociation constant (Kd value) of 0.1 nmol/l and a density of 300 fmol/mg of protein. The binding sites are stereoselective and discriminate between (+)-nitrendipine and (-)-nitrendipine. We conclude that a high-affinity binding site at which 1,4-dihydropyridines bind, has now been identified with radioligand binding techniques. This site may well represent the locus where the potent 1,4-dihydropyridines exert their pharmacological action.
氚标记的钙拮抗剂1,4 - 二氢 - 2,6 - 二甲基 - 4 -（3 - 硝基苯基）- 3,5 - 吡啶羧酸3 - 乙酯 - 5 - 甲酯（尼群地平，Bay e 5009），一种硝苯地平的有效类似物，以可逆和饱和的方式与部分纯化的豚鼠心脏膜结合。用Scatchard图分析平衡结合数据符合结合的负协同性或两类结合位点的假设，其中一个位点的平衡解离常数（Kd值）为0.1 nmol/l，蛋白质密度为300 fmol/mg。结合位点具有立体选择性，能区分（+）- 尼群地平和（-）- 尼群地平。我们得出结论，现已通过放射性配体结合技术鉴定出一个1,4 -二氢吡啶结合的高亲和力结合位点。该位点很可能代表强效1,4 - 二氢吡啶发挥其药理作用的部位。
