ADMA
Competitive 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: 90 min at room temperature
2. ELISA: over night incubation at 2 – 8 °C
Standard range: 0.1 µmol/l – 5.0 µmol/l
Kit controls 2 controls, ready for use
Characteristics
Competitive ADMA ELISA with microtiter plate format.
Highly specific and sensitive rabbit anti-ADMA antibody
Exceptionally good correlation to LC-MS-MS and GCMS
No interference with any therapeutic drugs
Good linearity between 0.1 µM – 5 µM
No crossreactivity to L-arginine, SDMA and N-monomethylarginine
Easy to handle, assay time is overnight.
Suitable for testing large series of serum or plasma samples
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.
- J. M. Wenzlau et al “The cation efflux transporter ZnT8 (Slc30A8) is a major autoantigen in
human type I diabetes.” PNAS 2007 104:17040-17045 - P. Achenbach et al “Autoantibodies to zinc transporter 8 and SLc30A8 genotype stratify type
1 diabetes risk.” Diabetologia 2009 52:1881-1888 - J. M. Wenzlau et al “Kinetics of the post-onset decline in zinc transporter 8 autoantibodies in type 1 diabetic human subjects.” J Clin Endocrinol Metab 2010 95:4712 – 4719
- L. Petruzelkova et al “The dynamic changes of zinc transporter 8 autoantibodies in Czech children for the onset of type 1 diabetes mellitus.” Diabet Med 2014 31:165 – 71
- G. Dunseath et al “Bridging-type enzyme-linked immunoassay for zinc transporter 8 autoantibody measurements in adult patients with diabetes mellitus.” Clin. Chim. Acta. 2015 447:90 – 95