HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) All Versions of this Article: iovs.07-1363v1 49/6/2506    most recent Submit a response Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Fernández-Durango, R. Articles by Leza, J. C. Search for Related Content PubMed PubMed Citation Articles by Fernández-Durango, R. Articles by Leza, J. C.

Expression of Nitrotyrosine and Oxidative Consequences in the Trabecular Meshwork of Patients with Primary Open-Angle Glaucoma

¹From the Research Unit, Department Internal Medicine III, Hospital Clínico San Carlos, Madrid, Spain; the ²Department of Ophthalmology, Hospital Clínico San Carlos, Madrid, Spain; and the ³Department of Pharmacology, Faculty of Medicine, Universidad Complutense, Madrid, Spain.

PURPOSE. To evaluate the possible correlation between the visual field defects in patients with primary open-angle glaucoma (POAG) and the expression and enzymatic activity of nitric oxide synthase (NOS) isoenzymes and nitrotyrosine in trabecular meshwork (TM) samples.

METHODS. TM specimens were collected from 146 patients with POAG by using standard filtration surgery. Visual field defects were evaluated by perimetry. Expression of endothelial (e)NOS and inducible (i)NOS were evaluated by quantitative RT-PCR. Constitutive (Ca²⁺-dependent) and iNOS (Ca²⁺-independent) activities were measured by the conversion of L-[14C]-arginine to L-[14C]-citrulline. In four TM specimens from POAG-affected eyes and in three human donor control eyes, 3-nitrotyrosine was localized by immunohistochemistry. The marker of lipid peroxidation malondialdehyde (MDA) was measured by the thiobarbituric acid test in samples of aqueous humor (AH) from 48 patients with either POAG or cataracts.

RESULTS. The results showed an upregulation of iNOS and a downregulation of calcium-dependent NOS correlated with visual field defects. Expression and activity of iNOS increased in parallel with visual field defects. However, constitutive activity decreased as the visual field defect increased. Nitrotyrosine was observed only in the cells of the TM specimens from eyes with severe POAG.

CONCLUSIONS. The increased expression and activity of iNOS in the TM of patients with POAG are proportional to the visual field defect and could lead to the increased of nitrotyrosine levels which may serve as marker of oxidative stress in the progression of cell death of the TM in POAG.

This article has been cited by other articles:

				Y. He, J. Ge, and J. Tombran-Tink Mitochondrial Defects and Dysfunction in Calcium Regulation in Glaucomatous Trabecular Meshwork Cells Invest. Ophthalmol. Vis. Sci., November 1, 2008; 49(11): 4912 - 4922. [Abstract] [Full Text] [PDF]