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|Section2= }} 2-Deoxy-D-glucose is a glucose molecule which has the 2-hydroxyl group replaced by hydrogen, so that it cannot undergo further glycolysis. As such, it acts to competitively inhibit the production of glucose-6-PO4 from glucose at the phosphoglucoisomerase level. In most cells, glucose hexokinase phosphorylates 2-deoxyglucose, trapping the product 2-deoxyglucose-6-phosphate intracellularly (with exception of liver and kidney); thus, labeled forms of 2-deoxyglucose serve as a good marker for tissue glucose uptake and hexokinase activity. Many cancers have elevated glucose uptake and hexokinase levels. 2-Deoxyglucose labeled with tritium or carbon-14 has been a popular ligand for laboratory research in animal models, where distribution is assessed by tissue-slicing followed by autoradiography, sometimes in tandem with either conventional or electron microscopy. 2-DG is uptaken by the glucose transporters of the cell. Therefore, cells with higher glucose uptake, for example tumor cells, have also a higher uptake of 2-DG. Since 2-DG hampers cell growth, its use as a tumor therapeutic has been suggested, and in fact, 2-DG is in clinical trials A recent clinical trial showed 2-DG can be tolerated at a dose of 63 mg/kg/day, however the observed cardiac side-effects (prolongation of the Q-T interval) at this dose and the fact that a majority of patients' (66%) cancer progressed casts doubt on the feasibility of this reagent for further clinical use.〔http://www.ncbi.nlm.nih.gov/pubmed/23228990〕 However, it is not completely clear how 2-DG inhibits cell growth. The fact that glycolysis is inhibited by 2-DG, seems not to be sufficient to explain why 2-DG treated cells stop growing 〔M Ralser, MM Wamelink, EA Struys, C Joppich, S Krobitsch, C Jakobs, H Lehrach Proc Natl Acad Sci U S A, 2008, 〕 Clinicians have noted that 2-DG is metabolised in the pentose phosphate pathway in red blood cells at least, although the significance of this for other cell types and for cancer treatment in general is unclear.〔(JD O'Dea )〕 Work on the ketogenic diet as a treatment for epilepsy have investigated the role of glycolysis in the disease. 2-Deoxyglucose has been proposed by Garriga-Canut et al. as a mimic for the ketogenic diet, and shows great promise as a new anti-epileptic drug.〔Mireia Garriga-Canut, Barry Schoenike, Romena Qazi, Karen Bergendahl, Timothy J Daley, Rebecca M Pfender, John F Morrison, Jeffrey Ockuly, Carl Stafstrom, Thomas Sutula & Avtar Roopra, "2-Deoxy-D-glucose reduces epilepsy progression by NRSF-CtBP–dependent metabolic regulation of chromatin structure", ''Nat Neurosci'', 9, 1382 - 1387 (2006). 〕 The authors suggest that 2-DG works, in part, by increasing the expression of Brain-derived neurotrophic factor (BDNF), Nerve growth factor (NGF), Arc (protein) (ARC), and Basic fibroblast growth factor (FGF2).〔Jia Yao, Shuhua Chen, Zisu Mao, Enrique Cadenas, Roberta Diaz Brinton "2-Deoxy-D-Glucose Treatment Induces Ketogenesis, Sustains Mitochondrial Function, and Reduces Pathology in Female Mouse Model of Alzheimer's Disease", ''PLOS ONE''〕 Such uses are complicated by the fact that 2-deoxyglucose does have some toxicity. 2-DG has been used as a targeted optical imaging agent for fluorescent ''in vivo'' imaging.〔Kovar, J., Volcheck, W., Sevick-Muraca, E., Simpson, M.A., and Olive, D.M., Analytical Biochemistry, Vol. 384 (2009) 254-262 (Download PDF )〕〔Cheng, Z., Levi, J., Xiong, Z., Gheysens, O., Keren, S., Chen, X., and Gambhir, S., Bioconjugate Chemistry, 17(3), (2006), 662-669〕 In clinical medical imaging (PET scanning), fluorodeoxyglucose is used, where one of the 2-hydrogens of 2-deoxy-D-glucose is replaced with the positron-emitting isotope fluorine-18, which emits paired gamma rays, allowing distribution of the tracer to be imaged by external gamma camera(s). This is increasingly done in tandem with a CT function which is part of the same PET/CT machine, to allow better localization of small-volume tissue glucose-uptake differences. ==References== 〔 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「2-Deoxy-D-glucose」の詳細全文を読む スポンサード リンク
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