Gibson R E, Schneidau T A, Gitler M, Zeeberg B, Reba R C
Department of Radiology, George Washington University Medical Center, Washington, D.C. 20037.
Life Sci. 1994;54(23):1757-65. doi: 10.1016/0024-3205(94)90114-7.
We have determined the binding of (R)-3-Quinuclidinyl 8-xanthenecarboxylate to muscarinic acetylcholine receptor preparations from rat cortex, hippocampus, caudate/putamen, thalamus, pons and colliculate bodies. The competition curves determined with [3H]quinuclidinyl benzilate as the radioligand are well described by a two site model with a difference in affinity between the two sites of 12-fold. The proportions of high affinity site vary from 100% in the caudate/putamen to 0% in the pons/medulla. The selectivities are different from those measured by pirenzepine and are consistent with QNX exhibiting similar affinity for the M1, M3, and M4 receptors with lower affinity for the M2 receptor. This assignment was confirmed by determining the affinities of QNX for the cloned receptor subtypes.
我们已经测定了（R）-3-喹核醇基8-呫吨羧酸酯与大鼠皮层、海马体、尾状核/壳核、丘脑、脑桥和丘状体中毒蕈碱型乙酰胆碱受体制剂的结合情况。以[³H]喹核醇基苯甲酸酯作为放射性配体测定的竞争曲线，用双位点模型能很好地描述，两个位点的亲和力差异为12倍。高亲和力位点的比例从尾状核/壳核中的100%到脑桥/延髓中的0%不等。其选择性与哌仑西平测定的不同，并且与QNX对M1、M3和M4受体表现出相似亲和力，对M2受体亲和力较低一致。通过测定QNX对克隆的受体亚型的亲和力，证实了这一归属。
