Eglen R M, Whiting R L
Br J Pharmacol. 1987 Apr;90(4):701-7. doi: 10.1111/j.1476-5381.1987.tb11223.x.
The affinity of a number of 'selective' agonists and antagonists has been assessed at atrial or ileal muscarinic receptors by use of in vitro functional analysis. The most selective compound for ileal muscarinic receptors was silabenzhexol (approx. 50 fold), and to a lesser extent benzhexol (approx. 5 fold). Conversely, the most selective compound for the atrial muscarinic receptors was AF-DX 116 (approx. 6 fold). The novel M1-receptor antagonist, telenzepine and other antagonists such as propantheline and isopropamide did not distinguish between atrial and ileal receptors. Dicyclomine, adiphenine, hexahydroadiphenine and oxyphenonium exhibited competitive antagonism at atrial receptors but non-competitive antagonism at ileal receptors. No conclusions could, therefore, be drawn with regard to their selectivity. The agonists, arecaidine propargyl ester (APE), ethoxyethyltriethylammonium (EOE) and carbachol, exhibited some selectivity in potency but little difference in affinity. It is concluded that the study supports the existence of ileal and atrial muscarinic receptor subtypes. However, the use of dicyclomine and related compounds in receptor classification is limited.
通过体外功能分析评估了多种“选择性”激动剂和拮抗剂对心房或回肠毒蕈碱受体的亲和力。对回肠毒蕈碱受体最具选择性的化合物是西拉苄醇（约50倍），其次是苄醇（约5倍）。相反，对心房毒蕈碱受体最具选择性的化合物是AF-DX 116（约6倍）。新型M1受体拮抗剂替仑西平以及其他拮抗剂如丙胺太林和异丙胺酰胺无法区分心房和回肠受体。双环胺、阿地芬宁、六氢阿地芬宁和奥芬溴铵在心房受体上表现出竞争性拮抗作用，但在回肠受体上表现出非竞争性拮抗作用。因此，无法就它们的选择性得出结论。激动剂槟榔碱炔丙酯（APE）、乙氧基乙基三乙铵（EOE）和卡巴胆碱在效力上表现出一定的选择性，但在亲和力上差异不大。结论是，该研究支持回肠和心房毒蕈碱受体亚型的存在。然而，双环胺及相关化合物在受体分类中的应用有限。
