Smith T L, Yamamura H I
Veterans Administration Medical Center, Tucson, AZ 85723.
Brain Res. 1987 Sep 15;420(2):362-4. doi: 10.1016/0006-8993(87)91257-1.
Carbamylcholine stimulated [3H]inositol phosphate accumulation in mouse cerebral cortical slices with an ED50 value of approximately 70 microM. Increasing concentrations of the M2 selective muscarinic cholinergic receptor antagonist, AF-DX 116 (0.3-3.0 microM). produced parallel shifts to the right for concentration-response curves to carbamylcholine. A pA2 value for AF-DX 116 of 6.5 (low affinity) was obtained from Schild plot analysis. It is concluded that the M2 muscarinic receptor subtype, as defined by high affinity [3H]AF-DX 116 radioligand binding, is not appreciably coupled to polyphosphoinositide hydrolysis in the mouse cerebral cortex.
氨甲酰胆碱刺激小鼠大脑皮质切片中[3H]肌醇磷酸的积累，其半数有效剂量（ED50）值约为70微摩尔。M2选择性毒蕈碱胆碱能受体拮抗剂AF-DX 116（0.3 - 3.0微摩尔）浓度增加时，氨甲酰胆碱的浓度-反应曲线平行右移。通过Schild图分析得出AF-DX 116的pA2值为6.5（低亲和力）。结论是，由高亲和力[3H]AF-DX 116放射性配体结合所定义的M2毒蕈碱受体亚型在小鼠大脑皮质中与多磷酸肌醇水解没有明显偶联。
