Determination of asymmetric dimethylarginine (ADMA) using a novel ELISA assay.
Asymmetric dimethylarginine (ADMA) is an endogenous competitive inhibitor of nitric oxide synthase (NOS). Elevated ADMA plasma levels have been reported in connection with diseases associated with an impaired endothelial L-arginine-NO pathway and endothelial dysfunction, such as atherosclerosis, hypercholesterolemia, chronic heart failure, diabetes mellitus, and hypertension. NO production by NOS is decreased due to elevated ADMA levels. In fact, there is increasing interest in determination of ADMA levels in samples of various origins. The aim of this work was to develop a precise and easy immunoassay in contrast to the existing methods, such as HPLC, liquid chromatography-mass spectrometry (LC-MS) and gas chromatography (GC)-MS. We determined cross-reactivity in our immunoassay of 1.2% for symmetric dimethylarginine and <0.02% for L-arginine. The limit of quantitation was 0.05 micromol/l. We found good correlation of the values measured when we compared our assay with LC-tandem MS (n = 29; r = 0.984; p < 0.0001). We determined ADMA levels in human serum and plasma, mouse and rat plasma, and cell culture supernatant. For human plasma we found a mean of 0.65 micromol/l in healthy subjects. In the plasma of mice and rats we found mean concentrations of 1.05 and 1.09 micromol/l, respectively.
Schulze
Friedrich
F
Clinical Pharmacology Unit, Institute of Experimental and Clinical Pharmacology, Center for Experimental Medicine, University Hospital Hamburg-Eppendorf, Hamburg, Germany.
Wesemann
Reinhard
R
Schwedhelm
Edzard
E
Sydow
Karsten
K
Albsmeier
Jennifer
J
Cooke
John P
JP
Böger
Rainer H
RH
D000818:Animals; D001120:Arginine / Q000031:analogs & derivatives* / Q000032:analysis / Q000097:blood*; D002478:Cells, Cultured; D003331:Coronary Vessels; D017077:Culture Media, Conditioned / Q000737:chemistry; D004730:Endothelium, Vascular / Q000737:chemistry; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D006801:Humans; D016014:Linear Models; D051379:Mice; D015394:Molecular Structure; D009569:Nitric Oxide / Q000097:blood; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors / Q000097:blood; D051381:Rats; D012680:Sensitivity and Specificity
D017077:Culture Media, Conditioned; D009569:Nitric Oxide; C018524:N,N-dimethylarginine; D001120:Arginine; D019001:Nitric Oxide Synthase