EFFECTS OF 2-ALPHA-DHET AND ITS OPTICAL ISOMERS ON MUSCARINIC AND NICOTINIC RECEPTORS

The agent 2 alpha-(2', 2'-disubstituted-2'-hydroxy-ethoxy) tropane (2 alpha-DHET), its optical isomers and atropine were compared in their a bility to inhibit specific [H-3]QNB binding to muscarinic receptors of guinea pig ileum and to antagonize oxotremorine- and nicotine-induced contractions of isolated guinea pig ileum. A good correlation was obs erved between the affinities to muscarinic receptors and the antimusca rinic potencies in isolated guinea pig ileum. The binding data for 2 a lpha-DHET and its isomers were also consistent with their central and peripheral pharmacological activity in vivo. Compounds with 2'R config uration are more suitable to the stereostruture of the binding sites o f muscarinic receptors than that of 2'5 configuration.