title: Endothelin-1 and nitric oxide levels in patients with glaucoma.
abstract: OBJECTIVE
  To investigate the levels of endothelin-1 (ET-1) and nitric oxide (NO) in the aqueous humor and plasma of human eyes with different types of glaucoma: primary open-angle glaucoma (POAG) and chronic closed-angle glaucoma (CCAG).
  
  
  METHODS
  Patients were classified into 3 groups: group I comprised 35 patients with POAG, group II comprised 25 patients with CCAG, and 30 patients with senile cataract (group III) were used as a control group. Aqueous humor and corresponding plasma were analyzed for ET-1 and NO concentrations by enzyme-linked immunosorbent assay. A Bonferroni correction for multiple comparisons was performed.
  
  
  RESULTS
  There was no significant difference in plasma levels of either ET-1 or NO metabolites between the groups studied. ET-1 and NO were significantly elevated in the aqueous humor of patients with CCAG and POAG compared to the corresponding value in patients with cataract (p < 0.001). ET-1 and NO concentrations in the aqueous humor were more marked in CCAG than in POAG. NO levels were correlated with ET-1 in the aqueous humor of patients with glaucoma (p < 0.001).
  
  
  CONCLUSIONS
  Increased concentrations of ET-1 and NO in aqueous humor may be useful with POAG and CCAG. In addition, ET-1 and NO may have useful metabolite levels in the aqueous humor of POAG and CCAG patients as a result of glaucoma damage and may not be a cause of it.
authors.affiliation: Ophthalmology Center, Faculty of Medicine, Mansoura University, Mansoura, Egypt. asaadghanem@hotmail.com
authors.forename: Asaad A
authors.initials: AA
authors.lastname: Ghanem
authors.forename: Ahmed M
authors.initials: AM
authors.lastname: Elewa
authors.forename: Lmiaa F
authors.initials: LF
authors.lastname: Arafa
mesh_terms: D000368:Aged; D001082:Aqueous Humor / Q000378:metabolism*; D002908:Chronic Disease; D019332:Endothelin-1 / Q000097:blood*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D015812:Glaucoma, Angle-Closure / Q000097:blood*; D005902:Glaucoma, Open-Angle / Q000097:blood*; D006801:Humans; D007429:Intraocular Pressure; D008297:Male; D008875:Middle Aged; D009569:Nitric Oxide / Q000097:blood*; D011863:Radioimmunoassay
chemical_list: D019332:Endothelin-1; D009569:Nitric Oxide