Glutamate immunoreactivity in rat cerebral cortex is reversibly abolished by 6-diazo-5-oxo-L-norleucine (DON), an inhibitor of phosphate-activated glutaminaseF Conti and A Minelli Institute of Human Physiology, University of Ancona, Italy. Glutamate (Glu) immunocytochemistry has been widely used to identify presumed gluergic neurons and synapses, but several problems related to the fact that Glu is both a synaptic transmitter and a compound used for metabolic purposes are still unsolved. One of these concerns the intense perikaryal staining observed in perfusion-fixed tissue. Phosphate-activated glutaminase, a key enzyme for the synthesis of releasable glutamate, is inhibited by the diazoketone 6-diazo-5-oxo-L- norleucine (DON), which greatly reduces glutamate release. In the present experiments, DON was either injected intraparenchymally or applied epipially to the sensorimotor cortex of adult Sprague-Dawley rats at concentrations of 0.25-1 mM. Both intraparenchymal and epipial applications of the chemical abolished Glu immunoreactivity in neuron perikarya. Adjacent sections processed for cytochrome oxidase histochemistry, for aspartate immunoreactivity, or stained with thionine showed no changes. The effects of DON application are reversible, as shown in a second series of experiments in which, after 30 min of DON application, animals were allowed to survive for 5-10 days. In these cases, Glu immunoreactivity in cortical neurons was identical to that observed in normal untreated animals. The results reported here suggest that Glu immunoreactivity demonstrated by the present procedure in neuron perikarya is mainly due to Glu produced via phosphate-activated glutaminase.
Volume 42,
Issue 6,
pp. 717-726,
06/01/1994
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J. Masson, M. Darmon, A. Conjard, N. Chuhma, N. Ropert, M. Thoby-Brisson, A. S. Foutz, S. Parrot, G. M. Miller, R. Jorisch, et al. Mice lacking brain/kidney phosphate-activated glutaminase have impaired glutamatergic synaptic transmission, altered breathing, disorganized goal-directed behavior and die shortly after birth. J. Neurosci., April 26, 2006; 26(17): 4660 - 4671. [Abstract] [Full Text] [PDF] |
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M. Melone, F. Quagliano, P. Barbaresi, H. Varoqui, J. D. Erickson, and F. Conti Localization of the Glutamine Transporter SNAT1 in Rat Cerebral Cortex and Neighboring Structures, With a Note on its Localization in Human Cortex Cereb Cortex, May 1, 2004; 14(5): 562 - 574. [Abstract] [Full Text] [PDF] |
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F. A. Chaudhry, R. J. Reimer, and R. H. Edwards The glutamine commute: take the N line and transfer to the A J. Cell Biol., April 29, 2002; 157(3): 349 - 355. [Abstract] [Full Text] [PDF] |
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F. A. Chaudhry, D. Schmitz, R. J. Reimer, P. Larsson, A. T. Gray, R. Nicoll, M. Kavanaugh, and R. H. Edwards Glutamine Uptake by Neurons: Interaction of Protons with System A Transporters J. Neurosci., January 1, 2002; 22(1): 62 - 72. [Abstract] [Full Text] [PDF] |
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K. L. Behar and D. L. Rothman In Vivo Nuclear Magnetic Resonance Studies of Glutamate-{gamma}-Aminobutyric Acid-Glutamine Cycling in Rodent and Human Cortex: the Central Role of Glutamine J. Nutr., September 1, 2001; 131(9): 2498S - 2504. [Abstract] [Full Text] [PDF] |
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R. J. Reimer, F. A. Chaudhry, A. T. Gray, and R. H. Edwards Amino acid transport System A resembles System N in sequence but differs in mechanism PNAS, June 14, 2000; (2000) 140152797. [Abstract] [Full Text] |
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R. Y. N. Lee, E. R. Sawin, M. Chalfie, H. R. Horvitz, and L. Avery EAT-4, a Homolog of a Mammalian Sodium-Dependent Inorganic Phosphate Cotransporter, Is Necessary for Glutamatergic Neurotransmission in Caenorhabditis elegans J. Neurosci., January 1, 1999; 19(1): 159 - 167. [Abstract] [Full Text] [PDF] |
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R. J. Reimer, F. A. Chaudhry, A. T. Gray, and R. H. Edwards Amino acid transport System A resembles System N in sequence but differs in mechanism PNAS, July 5, 2000; 97(14): 7715 - 7720. [Abstract] [Full Text] [PDF] |
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F. A. Chaudhry, R. J. Reimer, and R. H. Edwards The glutamine commute: take the N line and transfer to the A J. Cell Biol., April 29, 2002; 157(3): 349 - 355. [Abstract] [Full Text] [PDF] |
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