Evaluation of [14C]phenylacetate as a prototype tracer for the measurement of glial metabolism in the rat brain
Evaluation of [14C]phenylacetate as a prototype tracer for the measurement of glial metabolism in the rat brain
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DOI：
10.1016/j.nucmedbio.2006.08.007
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发表时间：
2006-11-01
影响因子：
3.1
通讯作者：
Gee, Antony
中科院分区：
文献类型：
--
作者：
Inoue, Osamu;Hosoi, Rie;Gee, Antony
[C-14]苯乙酸酯被设计为测量胶质代谢的原型示踪剂，并与[C-14]乙酸酯的效力进行了比较。给正常大鼠静脉注射[C-14]苯乙酸酯或[C-14]乙酸酯，用解剖法测定血浆、大脑皮层、小脑及周围组织的放射性浓度。此外，我们还用放射自显影技术比较了大鼠脑内注射选择性神经胶质毒素--氟柠檬酸后，[C-14]苯乙酸酯在大鼠脑内的摄取。[C-14]苯乙酸酯被迅速吸收到大脑中，并在给药后20分钟内保持在高水平。在注射后1分钟，大脑皮层中[C-14]苯乙酸酯的水平约为[C-14]乙酸酯的3倍。向右侧纹状体微量注射氟柠檬酸可显著降低右侧纹状体对[C-14]苯乙酸酯和[C-14]乙酸酯的摄取。放射化学分析证实[C-14]苯乙酸酯在大鼠脑内迅速降解，在注射后1分钟，不到20%的放射性代表未代谢的[C-14]苯乙酸酯。这些结果表明，[C-14]苯乙酸酯被迅速吸收到大脑中，并被水解并转化为[C-14]乙酸酯。[C-14]苯乙酸酯可能有可能作为一种示踪剂来测量完整大脑中的胶质新陈代谢。(C)2006 Elsevier Inc.保留所有权利。
[C-14]Phenylacetate was designed as a prototype tracer for the measurement of glial metabolism, and its potency in comparison with that of [C-14]acetate was evaluated in this study. Normal rats were intravenously injected with [C-14]phenylacetate or [C-14]acetate, and radioactivity concentrations were measured in the plasma, cerebral cortex, cerebellum and peripheral tissues by dissection method. In addition, [C-14]phenylacetate uptake in the rat brain was compared by autoradiography with that of [C-14]acetate following the injection of fluorocitrate, a selective glial toxin, into the brain. [C-14]Phenylacetate was rapidly taken up into the brain and was retained at high levels up to 20 min postadministration. The levels of [C-14]phenylacetate in the cerebral cortex were about threefold higher than those of [C-14]acetate at 1 min postinjection. Microinjection of fluorocitrate into the right striatum resulted in a significant decrease of the uptake of both [C-14]phenylacetate and [C-14]acetate into the right striatum. Radiochemical analysis confirmed the rapid hydrolysis of [C-14] phenylacetate in the rat brain, with less than 20% of radioactivity representing unmetabolized [C-14] phenylacetate at 1 min postinjection. These results suggest that [C-14]phenylacetate is rapidly taken up into the brain and is hydrolyzed and converted to [C-14]acetate. [C-14] Phenylacetate may have the potential to serve as a tracer for the measurement of glial metabolism in an intact brain. (c) 2006 Elsevier Inc. All rights reserved.