N. Rawal et al., URINARY-EXCRETION OF N-G-DIMETHYLARGININES IN MULTIPLE-SCLEROSIS PATIENTS - PRELIMINARY-OBSERVATIONS, Journal of the neurological sciences, 129(2), 1995, pp. 186-191
The concentrations of N-G,N'(G)-dimethylarginine [Me(2)(sym)Arg] and N
-G,N-G-dimethylarginine [Me(2)(asym)Arg] were determined in the urine
samples from multiple sclerosis (MS) and control subjects, using a hig
hly sensitive HPLC post-column o-phthaldialdehyde derivatization metho
d. The presence of approximately equal amounts of both dimethylarginin
e isomers, of Arg concentration nearly half of Me(2)Arg, and of the un
detectable amount of N-G-monomethylarginine were the characteristic ur
inary excretion pattern in all human samples studied. The urinary excr
etion of Me(2)(asym)Arg and Me(2)(sym)Arg from MS (n = 9) and control
(n = 7) were analyzed: the mean values from the samples were approxima
tely 20% (for all MS) and 33% (for chronic-progressive MS) lower than
those from the control for both dimethylarginine-derivatives when comp
ared to the respective compounds. Although there were contrasting tren
ds between controls and MS patients in the relationship of urinary N-G
-dimethylarginines and myelin basic protein like material (MBPLM), the
correlations were not significant. Differences in the ratios of the c
oncentrations of the two dimethyl derivatives, Me(2)(sym)Arg/Me(2)(asy
m)Arg, were not significantly different between MS and control groups.
These findings warrant further investigation of possible links betwee
n urinary excretion of N-G-dimethylarginine and MBPLM in MS. The possi
ble significance of myelin metabolism in relation to urinary N-G-dimet
hylarginines in MS is discussed.