Cheng H C, Sastry B V
Arch Int Pharmacodyn Ther. 1976 Oct;223(2):246-59.
The nature of the antagonism of the D(-)R- and L(+)S-mandeloylcholines to acetylcholine (ACh) was investigated at the muscarinic receptors of the guinea-pig ileal longitudinal muscle. The nature of the inhibition of acetylcholinesterase (AChE) and serum cholinesterase (ChE) by the mandeloylcholines was also investigated. Both optical isomers of mandeloylcholine were reversible competitive antagonists of ACh at the muscarinic receptors. One molecule of mandeloylcholine combined with one receptor. The apparent affinities (1/KB, where KB = dissociation constant) of the mandeloylcholines were in the following order: homatropine greater than D(-)R-mandeloylcholine greater than DL(+/-)RS-mandeloylcholines = L(+)S-mandeloylcholine. Therefore, the mandeloylcholines were stereoselective for muscarinic receptors. The mandeloylcholines were (mixed) reversible inhibitors (competitive and noncompetitive) of ACh hydrolysis by AChE. There was no significant difference between the apparent K1 values of the mandeloylcholines in the inhibition of AChE. The mandeloylcholines were mixed reversible inhibitors (competitive and noncompetitive) of ChE. D(-)R-mandeloylcholine had a higher apparent K1 than its isomer.
在豚鼠回肠纵行肌的毒蕈碱受体上研究了D(-)R-和L(+)S-扁桃酰胆碱对乙酰胆碱（ACh）的拮抗性质。还研究了扁桃酰胆碱对乙酰胆碱酯酶（AChE）和血清胆碱酯酶（ChE）的抑制性质。扁桃酰胆碱的两种旋光异构体在毒蕈碱受体上均为ACh的可逆竞争性拮抗剂。一分子扁桃酰胆碱与一个受体结合。扁桃酰胆碱的表观亲和力（1/KB，其中KB =解离常数）顺序如下：后马托品大于D(-)R-扁桃酰胆碱大于DL(+/-)RS-扁桃酰胆碱 = L(+)S-扁桃酰胆碱。因此，扁桃酰胆碱对毒蕈碱受体具有立体选择性。扁桃酰胆碱是AChE水解ACh的（混合）可逆抑制剂（竞争性和非竞争性）。扁桃酰胆碱在抑制AChE方面的表观K1值之间无显著差异。扁桃酰胆碱是ChE的混合可逆抑制剂（竞争性和非竞争性）。D(-)R-扁桃酰胆碱的表观K1高于其异构体。
