Shimada M, Kawamoto S, Hirose Y, Nakanishi M, Watanabe H, Watanabe M
Department of Anatomy, Osaka Medical College, Japan.
Histochem J. 1994 Mar;26(3):207-12.
In order to observe glucose transport into the brain, 6-[N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)amino]-6-deoxyglucose (NBDG), a non-metabolizable and fluorescent glucose analogue, was injected intravenously into mice. After ascertaining that this glucose analogue is non-metabolizable in the brain, the NBDG contents in the blood and brain were measured quantitatively by spectrofluorimetry at 0, 0.5, 2, 5, 10 and 30 min after intravenous injection. The NBDG content in the blood decreased markedly with time, whereas in the brain it rapidly decreased, then gradually increased after 2 min. Glucose transport into the hippocampus was observed with a confocal laser scanning microscope. At 0.5 min, NBGD was seen to be highly concentrated on the vascular wall. Using the confocal mode, it was found that the fluorescence was unevenly distributed on the microvessel wall, suggesting local differences of glucose transport in the vascular wall. At 5 min, the fluoresent intensity of the vascular wall was markedly decreased, whereas relatively intense fluorescence was observed in the cerebral parenchyma of the stratum lacunosum-moleculare and stratum pyramidale of Ca3. At 10 min, a weak fluoresence was diffusely distributed in the hippocampus. As to the localization of NBDG in the brain, capillary endothelium (luminal and abluminal membrane), basement membrane, and the feet of the astrocytes are discussed.
为了观察葡萄糖向脑内的转运，将一种不可代谢的荧光葡萄糖类似物6-[N-(7-硝基苯并-2-恶唑-1,3-二氮杂环丁烷-4-基)氨基]-6-脱氧葡萄糖（NBDG）静脉注射到小鼠体内。在确定这种葡萄糖类似物在脑内不可代谢后，于静脉注射后0、0.5、2、5、10和30分钟，通过荧光分光光度法定量测定血液和脑内的NBDG含量。血液中的NBDG含量随时间显著下降，而脑内的NBDG含量则迅速下降，然后在2分钟后逐渐增加。用共聚焦激光扫描显微镜观察葡萄糖向海马体的转运。在0.5分钟时，可见NBGD高度集中在血管壁上。采用共聚焦模式发现，荧光在微血管壁上分布不均匀，提示血管壁上葡萄糖转运存在局部差异。在5分钟时，血管壁的荧光强度显著降低，而在Ca3层的分子层和锥体层的脑实质中观察到相对较强的荧光。在10分钟时，微弱的荧光弥漫分布于海马体中。关于NBDG在脑内的定位，讨论了毛细血管内皮（管腔膜和基底侧膜）、基底膜和星形胶质细胞的足突。
