title: Inducible and endothelial nitric synthetase expression and nitrotyrosine accumulation in iris vasculature of patients with primary open-angle glaucoma: a pilot study.
abstract: BACKGROUND
  The "double-faced" effect of nitric oxide (NO) is thought to play an important role in triggering and progression of glaucoma.
  
  
  METHODS
  Iris samples were obtained during iridectomy in 35 patients (mean age of 65.4±5.3 years) with diagnosed primary open-angle glaucoma (POAG). The controls were collected postmortem from 10 donors with a mean age of 62.2±1.9 years. Visual field defects were evaluated by perimetry. The Hodapp-Parrish-Anderson classification was used to divide patients into 3 visual field defect groups. The intraocular pressure was measured 3 times before surgery using applanation tonometry. The phenotype activity of nitric oxide synthase (NOS) isoenzymes (endothelial--eNOS and inducible--iNOS) and expression of nitrotyrosine in iris vasculature was assessed.
  
  
  RESULTS
  Significant differences were found between glaucoma patients and the controls in eNOS and iNOS activity (Mann-Whitney test, U=35.5, Z=-2.037, p=0.04 and U=21, Z=2.69, p=0.007, respectively). In addition, the results showed an upregulation of nitrotyrosine in the capillary endothelial cells in the study group, which was associated with the duration of diagnosed glaucoma (R-Spearman of 0.33, p=0.0047) and visual field mean defect MD (R-Spearman of 0.29, p=0.019). Moreover, the activity of nitrotyrosine was significantly correlated with iNOS immunoreactivity (R-Spearman of 0.5, p=0.0001). However, the iNOS activity significantly varied among Hodapp-Parrish-Anderson groups (p=0.03).
  
  
  CONCLUSIONS
  Our observations confirmed the association between glaucomatous disturbances and upregulation of iNOS, together with increased nitrotyrosine storage.
authors.affiliation: Ophthalmology Clinic and Department of Ophthalmology, School of Medicine in Katowice, Medical University of Silesia, Katowice, Poland.
authors.forename: Wojciech
authors.initials: W
authors.lastname: Rokicki
authors.affiliation: Department of Histology & Embryology, School of Medicine in Katowice, Katowice, Poland.
authors.forename: Małgorzata
authors.initials: M
authors.lastname: Żaba
authors.affiliation: Ophthalmology Clinic and Department of Ophthalmology, School of Medicine in Katowice, Medical University of Silesia, Katowice, Poland.
authors.forename: Dorota
authors.initials: D
authors.lastname: Wyględowska-Promieńska
authors.affiliation: Ophthalmology Clinic and Department of Ophthalmology, School of Medicine in Katowice, Medical University of Silesia, Katowice, Poland.
authors.forename: Adam
authors.initials: A
authors.lastname: Kabiesz
authors.affiliation: Department of Histology & Embryology, School of Medicine in Katowice, Katowice, Poland.
authors.forename: Edyta
authors.initials: E
authors.lastname: Reichman-Warmusz
authors.affiliation: Department of Histology & Embryology, School of Medicine in Katowice, Katowice, Poland.
authors.forename: Marlena
authors.initials: M
authors.lastname: Brzozowa
authors.affiliation: Department of Radiotherapy, Maria Skłodowska-Curie Memorial Cancer Center and Institute of Oncology, Gliwice Branch, Gliwice, Poland.
authors.forename: Wojciech
authors.initials: W
authors.lastname: Majewski
authors.affiliation: Department of Histology & Embryology, School of Medicine in Katowice, Katowice, Poland.
authors.forename: Romuald
authors.initials: R
authors.lastname: Wojnicz
mesh_terms: D000368:Aged; D018450:Disease Progression; D005260:Female; D015971:Gene Expression Regulation, Enzymologic; D005902:Glaucoma, Open-Angle / Q000378:metabolism*; D006801:Humans; D007498:Iris / Q000098:blood supply* / Q000201:enzymology*; D008297:Male; D008365:Manometry; D008875:Middle Aged; D052247:Nitric Oxide Synthase Type II / Q000378:metabolism*; D052250:Nitric Oxide Synthase Type III / Q000378:metabolism*; D010641:Phenotype; D010865:Pilot Projects; D011237:Predictive Value of Tests; D014443:Tyrosine / Q000031:analogs & derivatives* / Q000737:chemistry; D015854:Up-Regulation
chemical_list: C002744:3-nitrotyrosine; D014443:Tyrosine; C496319:NOS2 protein, human; C496314:NOS3 protein, human; D052247:Nitric Oxide Synthase Type II; D052250:Nitric Oxide Synthase Type III