新抗胆碱药（^3H）—三环哌酯对人胎脑皮层M受体的作用

目的：研究三环哌酯与８月龄胎脑皮层Ｍ受体的结合特性，并与ＱＮＢ及成人皮层作比较。方法：用放射配体受体结合试验，研究比较三环哌酯和ＱＮＢ与８月龄胎脑皮层Ｍ受体的饱和实验参数竞争性抑制实验参数及结合和解离动力学实验参数，结果：（＾３Ｈ）三环哌酯与胎及陂层的结合参数（Ｋｄ＝０．０３２ｎｍｏｌ／Ｌ，Ｂｍａｘ＝４２６ｐｍｏｌ／ｇ）与（＾３Ｈ）ＱＮＢ（Ｋｄ＝０．０６４ｎｍｏｌ／Ｌ，Ｂｍａｘ＝４３４ｐｍｏｌ／ｇ

The effect of a new anticholinergic drug tricyclopinate on human fetal cerebral cortex muscarinic receptors

Objective and Methods: The binding characteristics of the novel cholinergic antagonist tricyclopinate with muscarinic receptors from human fetal cerebral cortex at gestation of 8 months were investigated in comparison with 3H]QNB by performing radioligand binding assays. Results and Conclusion: As revealed by saturation experiments, the binding parameters oftricyclopinate(K d=0.032 nmol/L,B max =426 pmol/g) were similar to those of QNB (K d=0.064 nmol/L, B max =434 pmol/g). Both ligands fit one site model of receptor ligand interaction. Tricyclopinate showed a potency comparable to QNB in the inhibitry effect on muscarinic receptors. As compared with adult cortex, saturation, inhibition and kinetic experiments showed that the muscarinic receptors in fetal cortex had similar binding characteristics to those in adult cortex except that the B max value in the former was slightly lower.