Baulieu J L, Huguet F, Chalon S, Gerard P, Frangin Y, Besnard J C, Pourcelot L, Guilloteau D
INSERM U316, UER de Médecine, Tours, France.
Int J Rad Appl Instrum B. 1990;17(5):511-4. doi: 10.1016/0883-2897(90)90172-w.
Radioiodinated m-iodobenzylguanidine [( 125I]MIBG) and tritiated norepinephrine [( 3H]NE]) uptake and release were compared, in different regions of the brain of the rat. The classification of the regions according to uptake was the same for both tracers:striatum greater than hypothalamus greater than hippocampus greater than cortex greater than brainstem. Tetrabenazine (TBZ), a granular monoamine uptake inhibitor reduced the uptake in the different regions. The inhibition rate was higher for [3H]NE uptake than for [125I]MIBG. The spontaneous release was the same for [125I]MIBG and [3H]NE and was the lowest in the striatum. The K+ stimulated release of [3H]NE was more complete than the release of [125I]MIBG and was the most important in the striatum. From these results, it is inferred that MIBG enters the brain tissue via NE uptake mechanisms. It appears that MIBG is stored in the chromaffin granules, as NE, but also in the cytoplasm. A modified molecule derived from MIBG which would cross the blood-brain barrier, would then appear as a potential scintigraphic marker of monoamine uptake, storage and release.
比较了放射性碘化间碘苄胍[（125I）MIBG]和氚标记去甲肾上腺素[（3H）NE]在大鼠脑不同区域的摄取和释放情况。两种示踪剂根据摄取情况对区域的分类相同：纹状体大于下丘脑大于海马大于皮质大于脑干。颗粒型单胺摄取抑制剂丁苯那嗪（TBZ）降低了不同区域的摄取。对[3H]NE摄取的抑制率高于对[125I]MIBG的抑制率。[125I]MIBG和[3H]NE的自发释放相同，且在纹状体中最低。K+刺激的[3H]NE释放比[125I]MIBG的释放更完全，且在纹状体中最为显著。从这些结果可以推断，MIBG通过NE摄取机制进入脑组织。似乎MIBG与NE一样，也储存在嗜铬颗粒中，但也存在于细胞质中。一种源自MIBG且能穿过血脑屏障的修饰分子，可能会成为单胺摄取、储存和释放的潜在闪烁显像标记物。
