Increased plasma asymmetric dimethylarginine (ADMA) levels in retinal venous occlusive disease.
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.
Zinellu
Angelo
A
Department of Biomedical Sciences, University of Sassari, Osilo, Italy. angelozinellu@libero.it
Pinna
Antonio
A
Sotgia
Salvatore
S
Zinellu
Elisabetta
E
Usai
Maria Franca
MF
Carta
Francesco
F
Gaspa
Leonardo
L
Deiana
Luca
L
Carru
Ciriaco
C
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
C018524:N,N-dimethylarginine; D001120:Arginine; D003545:Cysteine