Kuster J E, Stevenson J I, Ward S J, D'Ambra T E, Haycock D A
Department of Neuroscience, Sterling Winthrop Pharmaceuticals Research Division, Sterling Winthrop Inc., Rensselaer, New York.
J Pharmacol Exp Ther. 1993 Mar;264(3):1352-63.
A binding assay for WIN 55212-2, an aminoalkylindole (AAI) with antinociceptive activity in rodents, is described. [3H]WIN 55212-2 bound to rat cerebellar membranes with a Kd of 2 nM and a maximum binding of 1.2 pmol/mg of protein. Specific binding in this filtration assay was greater than 90%, saturable, reversible, stereospecific, pH sensitive and heat labile. Binding was decreased by Na+, K+, Li+ and nonhydrolyzable analogs of GTP and increased by Mg++ and Ca++. The density of specific binding sites varied throughout the central nervous system with the highest found in the cerebellum, hippocampus and striatum and the lowest in the medulla/pons and spinal cord. The binding affinities of other AAIs for the WIN 55212-2 binding site correlated with their potencies for inhibiting neuronally stimulated contractions in the isolated mouse vas deferens. Of more than 60 compounds representing recognized neurotransmitter systems, only cannabinoids effectively inhibited binding. The effect of cannabinoids on AAI binding was consistent with competitive inhibition and suggests that AAI activity may be mediated in whole or in part by interaction with cannabinoid receptors. AAIs appear to represent a structurally novel class of compounds with which to study cannabinoid receptors.
本文描述了一种针对WIN 55212-2的结合试验，WIN 55212-2是一种在啮齿动物中具有抗伤害感受活性的氨基烷基吲哚（AAI）。[3H]WIN 55212-2与大鼠小脑膜结合，解离常数（Kd）为2 nM，最大结合量为1.2 pmol/mg蛋白质。在这种过滤试验中，特异性结合大于90%，具有饱和性、可逆性、立体特异性、pH敏感性和热不稳定性。Na+、K+、Li+和GTP的不可水解类似物会降低结合，而Mg++和Ca++会增加结合。特异性结合位点的密度在整个中枢神经系统中各不相同，在小脑、海马体和纹状体中最高，在延髓/脑桥和脊髓中最低。其他AAI对WIN 55212-2结合位点的结合亲和力与其抑制离体小鼠输精管中神经刺激收缩的效力相关。在代表公认神经递质系统的60多种化合物中，只有大麻素能有效抑制结合。大麻素对AAI结合的影响与竞争性抑制一致，表明AAI的活性可能全部或部分通过与大麻素受体的相互作用介导。AAI似乎代表了一类结构新颖的化合物，可用于研究大麻素受体。
