Steroidal thiazolium salts were prepared and their interaction with [3H]N-methylscopolamine ([3H]NMS) at M2 muscarinic receptors using radioligand binding were studied. The results were consistent with a ternary complex theory. The compounds diminished [3H]NMS binding with Kd values in the micromolar or submicromolar range. In particular, the presence of bulky benzylic group at the thiazole nitrogen atom caused a substantial increase in affinity of allosteric ligand for receptor. Our results demonstrate that steroidal thiazolium salts could be a new class of potentially useful tools for mapping the muscarinic receptors.
制备了类
固醇噻唑盐,并使用放射
配体结合研究了它们与M
2毒蕈碱受体中的[
3H]N-
甲基莨菪碱([
3H]NMS)的相互作用。结果与三元复合物理论一致。这些化合物使[
3H]NMS的结合受体亲和力(K
d值)降低到微摩尔或亚微摩尔范围。特别是,
噻唑氮原子上的笨重
苄基团的存在导致了变构
配体与受体的亲和力显著增加。我们的研究结果表明,类
固醇噻唑盐可能是一种用于映射毒蕈碱受体的新型潜在工具类别。