title: Cytosolic reducing power preserves glutamate in retina.
abstract: Glutamate in neurons is an important excitatory neurotransmitter, but it also is a key metabolite. We investigated how glutamate in a neural tissue is protected from catabolism. Flux analysis using (13)C-labeled fuels revealed that retinas use activities of the malate aspartate shuttle to protect >98% of their glutamate from oxidation in mitochondria. Isolation of glutamate from the oxidative pathway relies on cytosolic NADH/NAD(+), which is influenced by extracellular glucose, lactate, and pyruvate.
authors.affiliation: Departments of Biochemistry, Pharmacology, Chemistry, and Ophthalmology, University of Washington, Seattle, WA 98195.
authors.forename: Jianhai
authors.initials: J
authors.lastname: Du
authors.forename: Whitney
authors.initials: W
authors.lastname: Cleghorn
authors.forename: Laura
authors.initials: L
authors.lastname: Contreras
authors.forename: Jonathan D
authors.initials: JD
authors.lastname: Linton
authors.forename: Guy C-K
authors.initials: GC
authors.lastname: Chan
authors.forename: Andrei O
authors.initials: AO
authors.lastname: Chertov
authors.forename: Takeyori
authors.initials: T
authors.lastname: Saheki
authors.forename: Viren
authors.initials: V
authors.lastname: Govindaraju
authors.forename: Martin
authors.initials: M
authors.lastname: Sadilek
authors.forename: Jorgina
authors.initials: J
authors.lastname: Satrústegui
authors.forename: James B
authors.initials: JB
authors.lastname: Hurley
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D002247:Carbon Isotopes / Q000378:metabolism; D003600:Cytosol / Q000378:metabolism*; D008401:Gas Chromatography-Mass Spectrometry; D018698:Glutamic Acid / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D064688:Metabolic Flux Analysis; D051379:Mice; D008810:Mice, Inbred C57BL; D008954:Models, Biological; D010084:Oxidation-Reduction; D012160:Retina / Q000378:metabolism*
chemical_list: D002247:Carbon Isotopes; D018698:Glutamic Acid