Zeller K, Rahner-Welsch S, Kuschinsky W
Department of Physiology, University of Heidelberg, Germany.
J Cereb Blood Flow Metab. 1997 Feb;17(2):204-9. doi: 10.1097/00004647-199702000-00010.
Glut1 is a specific transporter system that mediates glucose transfer across the blood-brain barrier (BBB). Although the main location of Glut1 is in the capillary endothelium of the brain, its local distribution in different brain regions is not as well defined. In the present investigation, the local pattern of Glut1 distribution was determined in 13 brain structures using an immunoautoradiographic method developed for this purpose. A polyclonal antibody directed against the C-terminal amino acid sequence of Glut1 was applied to cryosections of rat brains. A secondary antibody was added that had been coupled to [35S]. Results show a heterogeneous distribution of Glut1 in the brain with activities of [35S] ranging from 65% below to 15% above the mean. White matter activity was lower than gray matter activity. For comparison, capillary sections were counted in corresponding cryosections by indirect immunofluorescence using fibronectin antibodies. In addition, local cerebral glucose utilization (LCGU) was analyzed in identical brain structures of conscious rats by the quantitative autoradiographic 2-deoxyglucose method. Significant correlations were found between Glut1 density and either LCGU or capillary density. Results indicate a tight coupling of Glut1 transporter density and capillary density to the LCGU of different BBB structures in adult rats.
葡萄糖转运蛋白1（Glut1）是一种特异性转运系统，介导葡萄糖穿过血脑屏障（BBB）。虽然Glut1主要位于脑毛细血管内皮，但它在不同脑区的局部分布并不十分明确。在本研究中，采用为此目的开发的免疫放射自显影方法，在13个脑结构中确定了Glut1的局部分布模式。将针对Glut1 C末端氨基酸序列的多克隆抗体应用于大鼠脑冷冻切片。加入与[35S]偶联的二抗。结果显示Glut1在脑中呈异质性分布，[35S]活性范围在平均值以下65%至平均值以上15%之间。白质活性低于灰质活性。为作比较，使用纤连蛋白抗体通过间接免疫荧光法在相应冷冻切片中对毛细血管切片进行计数。此外，采用定量放射自显影2-脱氧葡萄糖法在清醒大鼠的相同脑结构中分析局部脑葡萄糖利用（LCGU）情况。发现Glut1密度与LCGU或毛细血管密度之间存在显著相关性。结果表明，成年大鼠中Glut1转运体密度和毛细血管密度与不同血脑屏障结构的LCGU紧密相关。
