Poppe R, Karbach U, Gambaryan S, Wiesinger H, Lutzenburg M, Kraemer M, Witte O W, Koepsell H
Anatomisches Institut, Bayerische Julius-Maximilians-Universität, Würzburg, Germany.
J Neurochem. 1997 Jul;69(1):84-94. doi: 10.1046/j.1471-4159.1997.69010084.x.
In brains of the rabbit, pig, and human, expression of the high-affinity Na+-D-glucose cotransporter SGLT1 and of the protein RS1, which alters the activity of SGLT1, was demonstrated. In situ hybridization showed that SGLT1 and RS1 are transcribed in pyramidal cells of brain cortex and hippocampus and in Purkinje cells of cerebellum. In neurons of pig brain SGLT1 protein was demonstrated by western blotting with synaptosomal membranes and by immunohistochemistry, which showed SGLT1 in pyramidal and Purkinje cells. To test whether SGLT1 in neurons may be activated during increased D-glucose consumption, an epileptic seizure was induced in rat brain, and the uptake of specific nonmetabolized substrates of SGLT1 [[14C]methyl-alpha-D-glucopyranoside ([14C]AMG)] and of Na+-independent transporters [2-deoxy-D-[14C] glucose ([14C]2-DG)] was analyzed by autoradiography. During the seizure the uptake of AMG and 2-DG was increased in the focus. Within two hours after the seizure 2-DG uptake in the focus returned to normal. In contrast, the AMG uptake in the focus area was still increased 1 day later. The data show that the high-affinity Na+-D-glucose cotransporter SGLT1 is expressed in neurons and can be up-regulated.
在兔、猪和人的大脑中，已证实了高亲和力的钠 - D - 葡萄糖协同转运蛋白SGLT1以及可改变SGLT1活性的RS1蛋白的表达。原位杂交显示，SGLT1和RS1在大脑皮层和海马体的锥体细胞以及小脑的浦肯野细胞中进行转录。在猪脑神经元中，通过对突触体膜进行蛋白质印迹法以及免疫组织化学方法证实了SGLT1蛋白的存在，免疫组织化学显示在锥体细胞和浦肯野细胞中有SGLT1。为了检测在D - 葡萄糖消耗增加期间神经元中的SGLT1是否会被激活，在大鼠脑中诱发癫痫发作，并通过放射自显影分析SGLT1的特定非代谢底物[[14C]甲基 - α - D - 吡喃葡萄糖苷([14C]AMG)]以及钠非依赖性转运蛋白[2 - 脱氧 - D - [14C]葡萄糖([14C]2 - DG)]的摄取情况。癫痫发作期间，病灶处AMG和2 - DG的摄取增加。癫痫发作后两小时内，病灶处2 - DG的摄取恢复正常。相比之下，病灶区域的AMG摄取在1天后仍增加。数据表明，高亲和力的钠 - D - 葡萄糖协同转运蛋白SGLT1在神经元中表达且可被上调。
