B-CIT在正常恒河猴体内分布的SPECT显像研究

SPECT Imaging Study of the Biodistribution of Beta-CIT in the Whole-Body of Healthy Rhesus Monkeys

目的研究多巴胺转运蛋白 (DAT)放射性配体12 3I-、131I- β -CIT在正常恒河猴体内的分布 ,探讨其临床应用前景。 方法于正常恒河猴肘静脉处弹丸注射12 3I- β-CIT(9mCi)或131I- β-CIT(10mCi)后 ,运用单光子发射计算机断层扫描仪 (SPECT)连续动态进行全身和头部断层扫描 ,计算各时间点感兴趣区 (ROI)的放射性计数。结果不同时间的断层扫描显示注射后 2 4h ,在纹状体部位的放射性浓集最清晰 ,纹状体 /额叶比值 1.78,左、右侧纹状体及与同侧额叶、颞叶和枕叶的比值基本相同 ;全身动态扫描显示 β -CIT主要分布在消化道 (胆囊和空、回肠 )。结论在脑内 β-CIT主要分布在纹状体 ,注射后 2 4h是脑断层扫描的最佳时间点 ;12 3I- β -CITSPECT在体显像可用于检测纹状体DAT的功能或密度。

Objective To investigate the biodistribution of dopamine transporter (DAT) radioactive ligand- 123 I-、 131 I-beta-CIT in the whole-body of healthy rhesus monkeys, and to explore the prospective of clinical practice of measuring the activity of DAT. Methods In vivo dynamic imaging was performed with single photon emission computed tomography (SPECT) after bolus intravenous injection of 123 I-beta-CIT(9mCi) or 131 I-beta-CIT(10mCi). The radioactivity of the region of interest at different times was calculated. Results The tomographic study showed the most accumulation of radioactivity in the striatum was at 24h after injection, and the ratio of striatum/frontal was 1.78. The whole-body dynamic imaging demonstrated the main biodistribution of beta-CIT was in the digestive system. No differences were found between the left striatum and the right one. The ratios of striatum/frontal or /temporal or /occipital were almost the same. Conclusion It was concluded that beta-CIT was distributed mainly in the striatum. 24h following the infusion of beta-CIT is the best point of time for brain imaging of DAT. In vivo SPECT scanning can be used for the detection of the function and density of striatal DAT with 123 I-beta-CIT.