Flesher J E, Scheffel U, London E D, Frost J J
Johns Hopkins Medical Institutions, Baltimore, MD 21287.
Life Sci. 1994;54(24):1883-90. doi: 10.1016/0024-3205(94)90146-5.
[3H]Cytisine was evaluated as an in vivo ligand for the nicotinic cholinergic receptor (nAchR) in mouse brain. The tracer was injected intravenously, and radioactivity in brain regions was analyzed. Radioactivity peaked in the brain at 30 minutes. It was highest in the thalamus, intermediate in the superior colliculi, prefrontal cortex and hippocampus, and low in the cerebellum. Pretreatment with unlabeled cytisine inhibited binding in the thalamus, but not in the cerebellum. Binding was displaced by l-nicotine, but not by d-nicotine or dexetimide. The results suggest that cytisine, appropriately labeled with a positron emitting radionuclide, may be useful for study of nicotinic cholinergic receptors in humans by emission computed tomography.
[3H]金雀花碱被评估为小鼠脑中烟碱型胆碱能受体（nAchR）的体内配体。将该示踪剂静脉注射，并分析脑区的放射性。放射性在30分钟时在脑中达到峰值。在丘脑中最高，在上丘、前额叶皮层和海马体中居中，在小脑中较低。用未标记的金雀花碱预处理可抑制丘脑中的结合，但不抑制小脑中的结合。l-尼古丁可取代结合，但d-尼古丁或右美托咪定则不能。结果表明，用发射正电子的放射性核素适当标记的金雀花碱，可能有助于通过发射计算机断层扫描研究人类的烟碱型胆碱能受体。
