NORMAL DISTRIBUTION OF NICOTINIC ACETYLCHOLINE RECEPTORS IN NON-SMOKERS AND SMOKERS : 5IA-SPELT STUDY.

我们已经证明了123I-(S)-5-碘-3-（2-偶氮基甲氧基）吡啶，123I-5-碘-a -85380（123I- 5ia）在人脑中对体内尼古丁乙酰胆碱受体成像的适用性。123I-5IA在正常志愿者中的分布与已知的人类烟碱受体的分布是一致的。本研究旨在利用123I-5IA研究吸烟者高亲和力烟碱乙酰胆碱受体（nAChR）在戒烟前后的体内时间变化。受试者为4名无神经系统疾病的吸烟者（女性1名，男性3名，年龄26 ~ 30岁，平均28.3±2.1）。他们分别在戒烟后4小时和20天进行了两次动态SPECT （Picker, Prism 3000）研究。在两项研究中，所有患者都接受了一分钟静脉注射约150 MBq的123I-5IA。获得每个受试者的动脉输入函数，并使用双室模型确定123I-5IA u的动力学参数。更多数据来自6小时SPECT扫描。计算了123I-5IA的分布体积（Vt）（ml/ml），它与大脑中未占用的结合位点的数量有关，并与之前正常非吸烟者志愿者的结果进行了比较。吸烟者体内123I-5IA Vt （ml/ml）值见表1。在研究的两个步骤中，均观察到丘脑和脑干的Vt值最高。戒烟后的Vt值显著高于戒烟4小时的吸烟研究（p<0.01），吸烟者的Vt值显著低于正常不吸烟者（p<0.05）。戒烟后的Vt值无显著差异。以及那些不吸烟的人。综上所述，123I-5IA-SPECT在评估戒烟前后吸烟者大脑nAChR分布的定量时间变化方面是有价值的。戒烟20天后观察到nAChR的上调。少

We have demonstrated suitability of 123I-(S)-5-iodo-3-(2-azetidinylmethoxy) pyridine, 123I-5-iodo-A-85380(123I-5IA) to image in vivo nicotinic acetylcholine receptors in human brain. This distribution of 123I-5IA in normal volunteer was compatible with the known distribution of nicotinic receptors in humans. The present study was designed to demonstrate the in vivo temporal changes of high affinity nicotinic acetylcholine receptors (nAChR) in smokers before and after cigarette withdrawal using 123I-5IA. Subjects were four smokers free of any neurological diseases (1 female and 3 males, 26 to 30 yrs, mean 28.3+/-2.1). They underwent two dynamic SPECT (Picker, Prism 3000) studies, 4 hours after and 20 days after cigarette smoking withdrawal. All of them received a one-minute intravenous injection of approximately 150 MBq of 123I-5IA in both studies. Arterial input function was obtained for each subject and a two-compartment model was used to determine the kinetic parameters of 123I-5IA u … More sing data from 6 hours SPECT scan. The distribution volume (Vt)(ml/ml) of 123I-5IA, which is related to the number of unoccupied binding sites in the brain, was calculated and compared to previous results generated from normal non-smoker volunteers. The 123I-5IA Vt (ml/ml) values in the smokers are shown in Table 1. The highest Vt values were observed in thalamus and brain stem at both steps of the study. The Vt values were significantly higher after cigarette smoking withdrawal (p<0.01) as compared to the smoking study with 4 hours smoking withdrawal The Vt values from smokers were significant lower as compared to the values from normal non-smokers (p<0.05). No significant difference was observed between Vt values after cigarette smoking withdrawal. and those of the non-smokers. In conclusion, 123I-5IA-SPECT was valuable in assessing quantitative temporal changes of nAChR distribution in smoker's brain as measured before and after cigarette withdrawal. Up-regulation of nAChR was observed after 20 days cigarette withdrawal in the smokers. Less