Brooks D J, Gibbs J S, Sharp P, Herold S, Turton D R, Luthra S K, Kohner E M, Bloom S R, Jones T
J Cereb Blood Flow Metab. 1986 Apr;6(2):240-4. doi: 10.1038/jcbfm.1986.37.
Regional cerebral [11C]3-O-methyl-D-glucose ([11C]MeG) uptake kinetics have been measured in five insulin-dependent diabetic patients and four normal controls using positron emission tomography (PET). Concomitant measurement of regional cerebral blood volume and CBF enabled corrections for the presence of intravascular [11C]MeG signal in cerebral regions of interest to be carried out, and regional cerebral [11C]MeG unidirectional extraction fractions to be computed. Four of the five diabetic subjects were studied with their fasting plasma glucose level clamped at a normoglycaemic level (4 mM), and four were studied at hyperglycaemic plasma glucose levels (mean 13 mM). The four diabetic subjects whose fasting plasma glucose levels were clamped at a normoglycaemic level of 4 mM had mean fasting whole-brain, cortical, and white matter [11C]MeG extraction fractions of 15, 15, and 16%, respectively, values similar to those found for the four normal controls (whole brain, 14%; cortex, 13%; white matter, 17%). Mean regional cerebral [11C]MeG extraction fractions were significantly reduced in diabetic subjects during hyperglycaemia whether their plasma insulin levels were undetectable or whether they were raised by continuous intravenous insulin infusion. Such a reduction in [11C]MeG extraction under hyperglycaemic conditions can be explained entirely in terms of increased competition between [11C]MeG and D-glucose for the passive facilitated transport carrier system for hexoses across the blood-brain barrier (BBB). It is concluded that the number and affinity of D-glucose carriers present in the BBB are within normal limits in treated insulin-dependent diabetic subjects. In addition, insulin appears to have no effect on the transport of D-glucose across the BBB.
利用正电子发射断层扫描（PET）技术，对5名胰岛素依赖型糖尿病患者和4名正常对照者的局部脑区[11C]3 - O - 甲基 - D - 葡萄糖（[11C]MeG）摄取动力学进行了测量。同时测量局部脑血容量和脑血流量，以便对感兴趣脑区血管内[11C]MeG信号的存在进行校正，并计算局部脑区[11C]MeG单向摄取分数。5名糖尿病受试者中的4名在空腹血糖水平钳定在正常血糖水平（4 mM）时进行了研究，另外4名在高血糖血浆葡萄糖水平（平均13 mM）时进行了研究。4名空腹血糖水平钳定在4 mM正常血糖水平的糖尿病受试者，其空腹全脑、皮质和白质的[11C]MeG摄取分数分别为15%、15%和16%，这些值与4名正常对照者（全脑，14%；皮质，13%；白质，17%）的值相似。无论是血浆胰岛素水平检测不到还是通过持续静脉输注胰岛素使其升高，糖尿病受试者在高血糖期间局部脑区[11C]MeG摄取分数均显著降低。在高血糖条件下[11C]MeG摄取的这种降低完全可以用[11C]MeG和D - 葡萄糖对跨血脑屏障（BBB）的己糖被动易化转运载体系统的竞争增加来解释。得出的结论是，在接受治疗的胰岛素依赖型糖尿病受试者中，BBB中存在的D - 葡萄糖载体的数量和亲和力在正常范围内。此外，胰岛素似乎对D - 葡萄糖跨BBB的转运没有影响。
