|
|
||||||||
1 From the Department of Ophthalmology and Visual Science, University of Texas-Houston Health Science Center, Houston, Texas; and the 2 College of Optometry, University of Houston, Houston, Texas.
PURPOSE. To investigate the hypothesis that the pathophysiology for the death of retinal ganglion cells in glaucoma involves excitotoxic effects from elevated concentrations of vitreal glutamate.
METHODS. Experimental glaucoma was induced in the right eyes of 18 rhesus monkeys by argon laser treatments to the trabecular meshwork. After significant visual field defects and/or typical clinical glaucomatous changes had developed (1.513 months), the eyes were removed, and a sample (0.10.2 mL) of posterior vitreous was collected. Similar vitreous samples also were collected from eight untreated monkeys. The vitreous samples were analyzed in a masked fashion by high-pressure liquid chromatography in two independent laboratories. Mean levels of vitreal glutamate were determined for the treated and control eyes and differences between groups of eyes were evaluated by Students t-test.
RESULTS. The mean level (± SD) of vitreal glutamate in the eight untreated monkeys was 5.0 ± 2.0 µM. A similar level of 5.7 ± 1.8 µM was measured in the untreated eyes of monkeys with experimental glaucoma. In the glaucomatous eyes, the mean concentration of vitreal glutamate was 5.7 ± 2.6 µM, which was not significantly different from the concentrations in the control eyes.
CONCLUSIONS. Vitreal glutamate concentrations were not elevated in eyes with anatomic and functional damage from experimental glaucoma. This finding is in contradiction to previous reports that vitreal glutamate increases to toxic levels and probably contributes to glaucomatous damage of retinal ganglion cells.
This article has been cited by other articles:
![]() |
W. Fan, X. Li, and N. G. F. Cooper CaMKII{alpha}B Mediates a Survival Response in Retinal Ganglion Cells Subjected to a Glutamate Stimulus Invest. Ophthalmol. Vis. Sci., August 1, 2007; 48(8): 3854 - 3863. [Abstract] [Full Text] [PDF] |
||||
![]() |
R. K. P. Sullivan, E. WoldeMussie, L. Macnab, G. Ruiz, and D. V. Pow Evoked Expression of the Glutamate Transporter GLT-1c in Retinal Ganglion Cells in Human Glaucoma and in a Rat Model. Invest. Ophthalmol. Vis. Sci., September 1, 2006; 47(9): 3853 - 3859. [Abstract] [Full Text] [PDF] |
||||
![]() |
G. Tezel, X. Yang, and J. Cai Proteomic Identification of Oxidatively Modified Retinal Proteins in a Chronic Pressure-Induced Rat Model of Glaucoma Invest. Ophthalmol. Vis. Sci., September 1, 2005; 46(9): 3177 - 3187. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. Wamsley, B. T. Gabelt, D. B. Dahl, G. L. Case, R. W. Sherwood, C. A. May, M. R. Hernandez, and P. L. Kaufman Vitreous Glutamate Concentration and Axon Loss in Monkeys With Experimental Glaucoma Arch Ophthalmol, January 1, 2005; 123(1): 64 - 70. [Abstract] [Full Text] [PDF] |
||||
![]() |
X. Luo, A. Baba, T. Matsuda, and C. Romano Susceptibilities to and Mechanisms of Excitotoxic Cell Death of Adult Mouse Inner Retinal Neurons in Dissociated Culture Invest. Ophthalmol. Vis. Sci., December 1, 2004; 45(12): 4576 - 4582. [Abstract] [Full Text] [PDF] |
||||
![]() |
F. Shen, B. Chen, J. Danias, K. C. Lee, H. Lee, Y. Su, S. M. Podos, and T. W. Mittag Glutamate-Induced Glutamine Synthetase Expression in Retinal Muller Cells after Short-term Ocular Hypertension in the Rat Invest. Ophthalmol. Vis. Sci., September 1, 2004; 45(9): 3107 - 3112. [Abstract] [Full Text] [PDF] |
||||
![]() |
R. S. Harwerth, L. Carter-Dawson, E. L. Smith III, G. Barnes, W. F. Holt, and M. L. J. Crawford Neural Losses Correlated with Visual Losses in Clinical Perimetry Invest. Ophthalmol. Vis. Sci., September 1, 2004; 45(9): 3152 - 3160. [Abstract] [Full Text] [PDF] |
||||
![]() |
W. A. Hare, E. WoldeMussie, R. K. Lai, H. Ton, G. Ruiz, T. Chun, and L. Wheeler Efficacy and Safety of Memantine Treatment for Reduction of Changes Associated with Experimental Glaucoma in Monkey, I: Functional Measures Invest. Ophthalmol. Vis. Sci., August 1, 2004; 45(8): 2625 - 2639. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. H. Neufeld and B. Liu Glaucomatous Optic Neuropathy: When Glia Misbehave Neuroscientist, December 1, 2003; 9(6): 485 - 495. [Abstract] [PDF] |
||||
![]() |
F. Mabuchi, M. Aihara, M. R. Mackey, J. D. Lindsey, and R. N. Weinreb Optic Nerve Damage in Experimental Mouse Ocular Hypertension Invest. Ophthalmol. Vis. Sci., October 1, 2003; 44(10): 4321 - 4330. [Abstract] [Full Text] [PDF] |
||||
![]() |
P. Aoun, J. W. Simpkins, and N. Agarwal Role of PPAR-{gamma} Ligands In Neuroprotection against Glutamate-Induced Cytotoxicity in Retinal Ganglion Cells Invest. Ophthalmol. Vis. Sci., July 1, 2003; 44(7): 2999 - 3004. [Abstract] [Full Text] [PDF] |
||||
![]() |
R. A. Honkanen, S. Baruah, M. B. Zimmerman, C. L. Khanna, Y. K. Weaver, J. Narkiewicz, R. Waziri, K. M. Gehrs, T. A. Weingeist, H. C. Boldt, et al. Vitreous Amino Acid Concentrations in Patients With Glaucoma Undergoing Vitrectomy Arch Ophthalmol, February 1, 2003; 121(2): 183 - 188. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |