Micheletti R, Giudici L, Turconi M, Donetti A
Dept. of Pharmacology, Istituto De Angeli, Milano, Italy.
Br J Pharmacol. 1990 Jul;100(3):395-7. doi: 10.1111/j.1476-5381.1990.tb15816.x.
The muscarinic receptors responsible for two effects elicited by McN-A-343, i.e. the relaxation of the rat duodenum and the inhibition of the twitch contraction of rabbit vas deferens, were investigated by use of derivatives of 4-diphenyl acetoxy-N-methyl piperidine methobromide (4-DAMP). Both receptors had been previously identified as M1 on the basis of the high affinity shown towards pirenzepine. Schild analysis of antagonism revealed that the affinities of 4-DAMP and three of its analogues in the rat duodenum were significantly different from those estimated in rabbit vas deferens. These data indicate that distinct receptor subtypes mediate duodenal relaxation and vas deferens inhibition of twitch contraction and suggest that receptors classified as M1 by means of pirenzepine affinity constitute a heterogeneous population.
通过使用4-二苯基乙酰氧基-N-甲基哌啶甲基溴化物(4-DAMP)的衍生物,研究了负责McN-A-343引发的两种效应(即大鼠十二指肠松弛和兔输精管抽搐收缩抑制)的毒蕈碱受体。基于对哌仑西平显示的高亲和力,这两种受体先前均被鉴定为M1。拮抗作用的Schild分析表明,4-DAMP及其三种类似物在大鼠十二指肠中的亲和力与在兔输精管中估计的亲和力显著不同。这些数据表明,不同的受体亚型介导十二指肠松弛和输精管抽搐收缩抑制,并表明通过哌仑西平亲和力分类为M1的受体构成一个异质群体。