title: Increased plasma asymmetric dimethylarginine (ADMA) levels in retinal venous occlusive disease.
abstract: BACKGROUND
  We investigated the levels of the endogenous nitric oxide synthase inhibitor asymmetric dimethylarginine (ADMA), as well as homocysteine and cysteine thiols, in a cohort of subjects affected by retinal vein occlusion (RVO) disease.
  
  
  METHODS
  Capillary electrophoresis analysis was performed in both RVO subjects (n=54) and in a control group (n=32).
  
  
  RESULTS
  No differences were found between controls and patients; however, after categorisation for RVO type, central RVO (CRVO) patients showed higher levels of ADMA (0.710+/-0.139 micromol/L) than controls (0.635+/-0.117 micromol/L) and branch RVO patients (0.642+/-0.096 micromol/L). Moreover, cysteine plasma levels were also significantly higher in CRVO patients than in controls (265.8+/-46.9 vs. 226.7+/-51.9 micromol/L, p<0.01), while homocysteine plasma concentration was more or less identical in all groups.
  
  
  CONCLUSIONS
  We hypothesise that the elevated levels of cysteine in CRVO patients may post-translationally inhibit dimethylarginine dimethylaminohydrolase enzyme activity, as already described for homocysteine, thus contributing to the accumulation of ADMA in this patient group.
authors.affiliation: Department of Biomedical Sciences, University of Sassari, Osilo, Italy. angelozinellu@libero.it
authors.forename: Angelo
authors.initials: A
authors.lastname: Zinellu
authors.forename: Antonio
authors.initials: A
authors.lastname: Pinna
authors.forename: Salvatore
authors.initials: S
authors.lastname: Sotgia
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Zinellu
authors.forename: Maria Franca
authors.initials: MF
authors.lastname: Usai
authors.forename: Francesco
authors.initials: F
authors.lastname: Carta
authors.forename: Leonardo
authors.initials: L
authors.lastname: Gaspa
authors.forename: Luca
authors.initials: L
authors.lastname: Deiana
authors.forename: Ciriaco
authors.initials: C
authors.lastname: Carru
mesh_terms: D000368:Aged; D001120:Arginine / Q000031:analogs & derivatives* / Q000097:blood; D016022:Case-Control Studies; D015331:Cohort Studies; D003545:Cysteine / Q000097:blood; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012170:Retinal Vein Occlusion / Q000097:blood*; D012307:Risk Factors
chemical_list: C018524:N,N-dimethylarginine; D001120:Arginine; D003545:Cysteine