ADMA Fast
ADMA Fast, kompetitive enzyme immunoassay for the quantitative determination of endogenous asymmetric dimethylarginine (ADMA) in serum or EDTA-plasma.
Procedure
Sample volume: 20 µl patient serum or plasma
1. Acylation: 20 min at room temperature
2. ELISA: 145 min at room tempaerature
Standard range: 0.2 µmol/l – 3.0 µmol/l
2 Kit Controls, ready for use
Characteristics
Very fast assay; Results available within 3 hours
Automatable
Easy handling because of colur coded reagents
The vascular endothelium plays a central role in the regulation of vascular structure and function, mainly due to the formation of endothelium-derived nitric oxide (NO). NO has been named an “endogenous anti-atherogenic molecule” due to its diverse regulatory functions in vascular homeostasis.
NO is formed by the enzyme NO synthetase (NOS) from the amino acid precursor L-arginine. NOS activity can be downregulated by asymmetric dimethylarginine (ADMA), an endogenous inhibitor of NOS.
The effects of ADMA on NO synthesis and NO-mediated pathophysiological processes have been described in numerous experimental studies. Moreover, elevated ADMA levels in plasma have been found in clinical studies including patients with hypercholesterolemia, hypertension, chronic heart failure, chronic renal failure and other internal disorders.
Recent prospective and cross-sectional studies indicated that elevated ADMA levels are a risk factor for future cardiovascular events and total mortality. ADMA may have diagnostic relevance as a novel cardiovascular risk marker.
The competitive ADMA-ELISA uses the microtiter plate format. ADMA is bound to the solid phase of the microtiter plate. ADMA in the samples is acylated and competes with solid phase bound ADMA for a fixed number of rabbit anti-ADMA antiserum binding sites. When the system is in equilibrium, free antigen and free antigen-antiserum complexes are removed by washing. The antibody bound to the solid phase ADMA is detected by anti-rabbit/peroxidase. The substrate TMB / peroxidase reaction is monitored at 450 nm. The amount of antibody bound to the solid phase ADMA is inversely proportional to the ADMA concentration of the sample.
- Schulze F, Wesemann R, Schwedhelm E, Sydow K, Albsmeier J, Cooke JP, Böger RH.
Determination of ADMA using a novel ELISA assay. Clin. Chem. Lab. Med. 2004; 42: 1377-1383 - Krempl TK, Kähler J, Maas R, Silberhorn L, Meinertz T, Böger RH. Elevation of asymmetric dimethylarginine (ADMA) in patients with unstable angina and recurrent cardiovascular events. Eur. Heart J. 2005; 26: 1846-1851
- Schulze F, Maas R, Freese R, Schwedhelm E, Silberhorn L, Böger RH. Determination of a reference value for N,N-dimethyl-L-arginine in 500 subjects. Eur. J. Clin. Invest. 2005; 35 : 622-626
- Schnabel R, Blankenberg S, Lubos E, Lackner KJ, Rupprecht HJ, Espinola-Klein C, Jachmann N, Post F, Peetz D, Bickel C, Cambien F, Tiret L, Münzel T. Asymmetric dimethylarginine and the risk of cardiovascular events and death in patients with coronary artery disease: results from the AtheroGene Study. Circ. Res. 2005; 97: e53-59
- O`Dwyer MJ, Dempsey F, Crowley V, Kelleher D, McManus R, Ryan T. Septic shock correlates with ADMA levels which may be influenced by a polymorphism in DDAH II: a prospective observational study. Crit. Care 2006; 10: (5): R139