【摘要】 目的:应用PET诊断显像剂[¹¹C]4-乙酰氧基-N-甲基哌啶([¹¹C]MP4A)对转基因痴呆小鼠、老龄小鼠及猕猴进行活体脑乙酰胆碱酯酶（AChE）活性PET显像研究。方法:小鼠经静脉注射[¹¹C]MP4A后进行PET/CT扫描,采集图像测量并计算出各感兴趣区域放射总量百分比（%ID）,分析两组小鼠间及猕猴的PET显像差异与特点。扫描后即刻分离小鼠大脑、小脑和脑干,称重并测定¹¹C计数,计算放射性摄取率（%ID/g）,比较两组小鼠脑放射性摄取率分布差异。结果:两组小鼠放射性显像清晰,脑放射性聚集对称。转基因痴呆鼠脑中放射性聚集较老龄鼠稀疏。转基因小鼠和老龄鼠大脑平均放射性摄取率值分别为1.49%ID/g和2.62%ID/g,差异有统计学意义（P=0.025）。猕猴脑内放射性显像清晰,放射性物质对称浓聚于皮质下,皮质聚集中等。结论:小鼠和正常猕猴[¹¹C]MP4A PET显像清晰,放射性物质对称分布于皮质下,[¹¹C]MP4A可以活体显像脑AChE的活性。更多还原

【Abstract】 Aim:To in vivo show the activity of acetylcholinesterase in the brain of transgenic mice,aged mice and adult rhesus monkey by using N-[¹¹C]methyl-4-piperidylacetate([¹¹C]MP4A) and positron emission tomography（PET）.Methods:After[¹¹C]MP4A was injected through vein in the mice and monkey,those experimental animals were performed by sequential PET/CT scans.Radioactivity in regions of interest（ROI） were measured and expressed as a percentage of that in whole body（%ID）.The differences of%ID in ROIs were compared between groups.After PET scans,mice were decapitated immediately,and cerebrum,cerebellum and brainstem were collected.Each sample was weighted after radioactivity was measured.The radioactivity was expressed as%ID/g,and the distribution of radioactivity in brains of transgenic mice and aged mice was compared.Results:PET imaging showed that the radioligand accumulated symmetrically in the brains of both mice groups but more less in transgenic mice brain than that in aged mice brain.The average%ID/g values of cerebra in transgenic mice and aged mice were 1.49 and 2.62 respectively（P=0.025）.There was significant decrease of[¹¹C]MP4A in the brains of transgenic mice compared with that in aged mice.[¹¹C]MP4A PET imaging in the brain of rhesus monkey clearly showed that radioactive uptakes in brain were symmetrically distributed,mostly in subcortex and moderately in cortex.Conclusion:[¹¹C]MP4A PET imaging shows good quality in the brain of both mice and monkey.The radioactivity gathers more in subcortex than that in cortex, indicating that[¹¹C]MP4A is able to be used for the in vivo evaluation of the acetylcholinesterase activity in brain by PET.更多还原