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Pre-Analytical and Clinical Validation of a Dried Blood Spot Assay for Asymmetric Dimethylarginine and L-Arginine. J Clin Med 2020; 9:jcm9041072. [PMID: 32283799 PMCID: PMC7230730 DOI: 10.3390/jcm9041072] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Revised: 04/07/2020] [Accepted: 04/08/2020] [Indexed: 02/07/2023] Open
Abstract
Asymmetric dimethylarginine (ADMA) inhibits nitric oxide (NO) synthesis. It is a risk marker for cardiovascular events and mortality in patients with cardiometabolic diseases and in population-based studies. Plasma or serum analysis of ADMA may be hampered by pre-analytical sample handling. We validated a dried blood spot (DBS) assay for ADMA and L-arginine and show here that this assay has excellent variabilities and reproducibilities. Filter paper is impregnated with the arginase inhibitor nor-NOHA (Nω-hydroxy-nor-Arginine) to avoid L-arginine degradation. Clinical validation of this DBS assay confirms elevated ADMA concentration in hemodialysis patients as compared to healthy controls, higher ADMA concentrations in men versus women, and elevated L-arginine concentration in subjects supplemented with L-arginine. The DBS assay was used in a cohort study involving 100 primarily healthy subjects in the Andean region to assess the impact of chronic intermittent hypoxia on ADMA and L-arginine; ADMA DBS concentration at sea level was prospectively associated with pulmonary hypertension after six months of exposure to 3500 m. In a cohort of 753 individuals, L-arginine/ADMA ratio significantly decreased with increasing number of traditional cardiovascular risk factors. Analysis of ADMA and L-arginine in DBS is a reliable and reproducible method for quantitation of these markers in field studies.
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Raptis V, Georgianos PI, Sarafidis PA, Sioulis A, Makedou K, Makedou A, Grekas DM, Kapoulas S. Elevated asymmetric dimethylarginine is associated with oxidant stress aggravation in patients with early stage autosomal dominant polycystic kidney disease. Kidney Blood Press Res 2014; 38:72-82. [PMID: 24577239 DOI: 10.1159/000355756] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/10/2014] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND/AIMS In experimental models of polycystic kidney disease impaired bioavailability of nitric oxide (NO) and elevated mRNA expression of oxidative stress markers at the kidney level was noted. However, clinical studies investigating the potential role of endothelial dysfunction and oxidative stress in the pathogenesis of autosomal dominant polycystic kidney disease (ADPKD) are limited. We evaluated asymmetric dimethylarginine (ADMA) as marker of NO synthase inhibitor as well as 15-F2t-Isoprostane and oxidized-low density lipoprotein (oxidized-LDL) as measures of oxidative stress in patients with early stages ADPKD. METHODS We recruited 26 ADPKD patients (Group A) with modestly impaired renal function (eGFR 45-70 ml/min/1.73 m(2)), 26 age- and sex-matched ADPKD patients (Group B) with relatively preserved renal function (eGFR)>70 ml/min/1.73 m(2)), and 26 age- and sex-matched controls (Group C). Determination of circulating levels of ADMA, 15-F2t-Isoprostane, oxidized-LDL and routine biochemistry was performed. RESULTS Group A and B had significantly higher ADMA levels as compared to controls (1.68 ± 0.7 vs 0.51 ± 0.2 μmol/l, P<0.001 and 1.26 ± 0.7 vs 0.51 ± 0.2 μmol/l, P<0.001, respectively). 15-F2t-IsoP and oxidized-LDL levels were also significantly higher in Group B relative to controls (788.8 ± 185.0 vs 383.1 ± 86.0 pgr/ml, P<0.001 and 11.4 ± 6.6 vs 6.4 ± 2.6 EU/ml, P<0.05 respectively) and were further elevated in Group A. In correlation analysis, ADMA levels exhibited strong associations with levels of 15-F2t-Isoprostane (r=0.811, P<0.001) and oxidized-LDL (r=0.788, P<0.001), whereas an inverse correlation was evident between ADMA and eGFR (r=-0.460, P<0.001). CONCLUSION This study shows elevation in circulating levels of ADMA along with aggravation of oxidative stress from the early stages of ADPKD. © 2014 S. Karger AG, Basel.
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Affiliation(s)
- Vassilios Raptis
- Section of Nephrology and Hypertension, 1st Department of Medicine, AHEPA University Hospital, Thessaloniki, Greece
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Gervasoni J, Bonelli F, Zuppi C, Zappacosta B, Mordente A, Calvani R, Persichilli S. Determination of asymmetric dimethyl arginine in human serum by liquid chromatography-tandem mass spectrometry: clinical application in hypertensive subjects. Clin Chem Lab Med 2011; 49:2109-15. [PMID: 21892910 DOI: 10.1515/cclm.2011.691] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2011] [Accepted: 07/29/2011] [Indexed: 11/15/2022]
Abstract
BACKGROUND Asymmetric dimethylarginine (ADMA), an endogenous competitive inhibitor of nitric oxide synthase plays an important role in endothelial dysfunction processes. Recent studies have linked high ADMA levels with several pathological conditions. The interest as a marker of endothelial dysfunction has increased in the last few years. In this paper, a method for serum ADMA quantification by liquid chromatography tandem mass spectrometry has been described. To test the utility in a pathological condition ADMA levels in hypertensive subjects have been measured. METHODS HPLC separation was performed by hydrophilic interaction chromatography using acetonitrile/water containing 0.1% formic acid and 20 mmol/L ammonium formate. Selected reaction monitoring was performed following the transitions m/z 203.1→46.4 for ADMA and 210.1→46.3 for the internal standard [2H7]ADMA. RESULTS The method was linear up to 10 μmol/L, limit of detection and limit of quantification were 0.005 μmol/L and 0.01 μmol/L, respectively. Recovery was higher than 96%. Intra- and inter-assay imprecision were lower than 6%. The accuracy, expressed as bias %, was <2.5. ADMA in "healthy" subjects ranged from 0.343 to 0.608 μmol/L and resulted significantly lower than that measured in hypertensive subjects (p<0.001). CONCLUSIONS The method developed is selective and sensitive, thus suitable not only for research purposes, but also for routinely work.
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Affiliation(s)
- Jacopo Gervasoni
- Istituto di Biochimica e Biochimica Clinica, Universita` Cattolica del Sacro Cuore, Rome, Italy.
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Blackwell S. The biochemistry, measurement and current clinical significance of asymmetric dimethylarginine. Ann Clin Biochem 2009; 47:17-28. [PMID: 19940201 DOI: 10.1258/acb.2009.009196] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Asymmetric dimethylarginine (ADMA) is an endogenous competitive inhibitor of nitric oxide synthase and an important cause of endothelial dysfunction. Its increased plasma concentration is associated with a variety of traditional cardiovascular risk factors, and may mediate their effects on the vascular endothelium. ADMA is also an independent predictor of cardiovascular events and mortality, and predicts outcomes in critically ill patients in the intensive care unit. This work has provided insights into the role of ADMA as an endogenous regulator of nitric oxide synthesis. At present there is no specific therapy to modify ADMA concentration, but increasing interest and work on protein arginine methyltransferases and dimethylarginine dimethylaminohydrolase, which synthesize and metabolize ADMA, respectively, might provide novel therapeutic targets.
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Affiliation(s)
- Scott Blackwell
- Department of Clinical Biochemistry, Royal Infirmary, 84 Castle Street, Glasgow G4 0SF, UK.
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Wadham C, Mangoni AA. Dimethylarginine dimethylaminohydrolase regulation: a novel therapeutic target in cardiovascular disease. Expert Opin Drug Metab Toxicol 2009; 5:303-19. [PMID: 19331593 DOI: 10.1517/17425250902785172] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Asymmetric dimethylarginine (ADMA), an endogenous methylated form of the amino acid L-arginine, inhibits the activity of the enzyme endothelial nitric oxide synthase, with consequent reduced synthesis of nitric oxide. ADMA is metabolised to L-citrulline and dimethylamine by the enzyme dimethylarginine dimethylaminohydrolase (DDAH). The modulation of DDAH activity and expression plays a pivotal role in regulating intracellular ADMA concentrations, with important effects on vascular homeostasis. For example, impairment in DDAH activity, resulting in elevated ADMA concentrations and reduced nitric oxide synthesis, can promote the onset and progression of atherosclerosis in experimental models. This review discusses the current role of ADMA and DDAH in vascular health and disease, the techniques used to assess DDAH activity and expression, and the results of recent studies on pharmacological and biological agents modulating DDAH activity and expression. Suggestions for future basic and clinical research directions are also discussed.
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Affiliation(s)
- Carol Wadham
- Flinders University, Flinders Medical Centre, Department of Clinical Pharmacology, Adelaide, Australia
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Hewitson CL, Whiting MJ, Barbara JA, Mangoni AA. Acute effects of haemodialysis on biochemical modulators of endothelial function. J Intern Med 2007; 262:571-80. [PMID: 17949366 DOI: 10.1111/j.1365-2796.2007.01848.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVES To assess the acute effects of haemodialysis (HD) on biochemical factors modulating endothelial function. SETTING Academic medical centre. SUBJECTS Forty patients (age 63.5 +/- 2.2 years, mean +/- SEM) undergoing HD. INTERVENTIONS Folic acid (F), homocysteine (tHcy), asymmetric dimethylarginine (ADMA), high-sensitivity C-reactive protein (CRP) and malondialdehyde (MDA) were measured pre-HD, 1 h after commencing HD and within the last hour of HD (end-HD). Endothelium-dependent and -independent vasodilatation were measured by applanation tonometry (changes in augmentation index, AIx, postinhaled salbutamol and postsublingual nitroglycerin) in conjunction with biochemical measurements. RESULTS Marked reductions in serum F (616 +/- 73 vs. 273 +/- 30 nmol L(-1), P < 0.001), tHcy (16.3 +/- 0.7 vs. 11.2 +/- 0.5 micromol L(-1), P < 0.001) and ADMA (0.64 +/- 0.02 vs. 0.47 +/- 0.02 micromol L(-1), P < 0.001) occurred end-HD, whereas CRP and MDA levels did not significantly change. There was no significant change in endothelium-dependent vasodilatation, whereas endothelium-independent vasodilatation improved end-HD (-23.1 +/- 1.9 vs. -17.3 +/- 1.3%, P = 0.018). Regression analysis showed that both higher ADMA (P = 0.029) and lower F levels (P = 0.040) end-HD were determinants of reduced endothelium-dependent vasodilatation end-HD (R(2) = 0.23). CONCLUSIONS HD is associated with significant reductions in F, tHcy and ADMA serum concentrations. The lack of significant effects of HD on endothelium-dependent vasodilatation could be secondary to the concomitant loss of factors either enhancing (F) or impairing (ADMA) endothelial function.
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Affiliation(s)
- C L Hewitson
- Department of Clinical Pharmacology, Flinders University and Flinders Medical Centre, Adelaide, Australia
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Warnholtz A, Ostad MA, Heitzer T, Thuneke F, Fröhlich M, Tschentscher P, Schwedhelm E, Böger R, Meinertz T, Munzel T. AT1-receptor blockade with irbesartan improves peripheral but not coronary endothelial dysfunction in patients with stable coronary artery disease. Atherosclerosis 2007; 194:439-45. [PMID: 16970950 DOI: 10.1016/j.atherosclerosis.2006.08.034] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/24/2006] [Revised: 08/07/2006] [Accepted: 08/14/2006] [Indexed: 10/24/2022]
Abstract
Activation of the renin-angiotensin-aldosterone system plays an important role in the pathogenesis of endothelial dysfunction and atherosclerosis. Studies evaluating the effect of AT1-receptor blockers on endothelial dysfunction in patients with coronary artery disease (CAD) revealed mixed results. Studies addressing the effects of AT1-receptor blockers on the coronary and peripheral function in the same study population, are still lacking. We therefore aimed to test the effects of long-term therapy with the AT1-receptor blocker irbesartan (IRB) on both, the coronary and peripheral endothelial function in patients with CAD. Seventy-two patients with CAD were randomly assigned to double-blinded treatment for 6 months with IRB 300 mg per day or placebo, respectively. Coronary and peripheral endothelial function were measured by intracoronary infusion of acetylcholine (final intracoronary concentration 10(-7.3) to 10(-5.6)M) and by determining flow-dependent dilation (FMD) of the brachial artery, respectively. IRB significantly improved FMD, while no change of coronary endothelial function was observed. Interestingly, plasma levels of N(G),N(G)-dimethyl-arginine, and the isoprostane excretion rate were not modified. IRB treatment improves peripheral but not coronary endothelial dysfunction in patients with CAD. Since reduced FMD of the brachial artery has been shown to be associated with a high-cardiovascular event rate, improvement of FMD by IRB may lead to better prognosis of patients with CAD.
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Affiliation(s)
- Ascan Warnholtz
- Department of Medicine II, Johannes Gutenberg-University Mainz, Langenbeckstrasse 1, 55101 Mainz, Germany.
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Blackwell S, O'Reilly DSJ, Talwar D. Biological variation of asymmetric dimethylarginine and related arginine metabolites and analytical performance goals for their measurement in human plasma. Eur J Clin Invest 2007; 37:364-71. [PMID: 17461982 DOI: 10.1111/j.1365-2362.2007.01798.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND Asymmetric dimethylarginine (ADMA) is an endogenous competitive inhibitor of nitric oxide synthase which is believed to be a cause of endothelial dysfunction and has been shown to predict the occurrence of acute coronary events. Data regarding the biological variation of arginine and its methylated derivatives are conspicuously absent from the literature. Such data are important in setting analytical quality specifications, assessing the utility of population reference intervals and assessing the significance of changes in serial results from an individual. MATERIALS AND METHODS Arginine, homoarginine, ADMA and symmetric dimethylarginine (SDMA) are measured in plasma by high performance liquid chromatography. Twelve healthy volunteers underwent weekly blood sampling for 20 weeks in order to determine the intra- and inter-individual biological variation of these analytes, from which analytical quality specifications, indices of individuality (II) and reference change values (RCV) are derived. Plasma samples from 100 healthy individuals were obtained in order to determine population reference intervals. RESULTS ADMA and symmetric dimethylarginine (SDMA) exhibit low intra-individual biological variation of 7.4% and 5.8%, respectively, imposing desirable imprecision goals (CV(A)) of < or = 3.7% and 2.9% for these analytes. The described methodology achieves these goals, with analytical CVs of < 3.5% for all analytes. Goals for bias and total error were 3.1-10.1% and 7.2-16.0%, respectively. Reference intervals for ADMA and SDMA were 0.29-0.63 micromol L(-1) and 0.24-0.55 micromol L(-1), but have IIs < 1. RCVs were at least 20% for all analytes studied. CONCLUSIONS Dimethylarginine concentrations are tightly controlled in health, with the result that imprecision goals for laboratory methods require to be low. Relatively large differences are required between serial results to denote a significant change. Population reference intervals for dimethylarginines are likely to be of limited value in detecting 'abnormality' in an individual from a single result.
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Wang S, Vicente FB, Miller A, Brooks ER, Price HE, Smith FA. Measurement of arginine derivatives in pediatric patients with chronic kidney disease using high-performance liquid chromatography-tandem mass spectrometry. ACTA ACUST UNITED AC 2007; 45:1305-12. [PMID: 17663630 DOI: 10.1515/cclm.2007.277] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
AbstractClin Chem Lab Med 2007;45:1305–12.
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Affiliation(s)
- Sihe Wang
- Department of Pathology and Laboratory Medicine, Children's Memorial Hospital, Northwestern University Feinberg School of Medicine, Chicago, IL, USA.
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Giustarini D, Milzani A, Dalle-Donne I, Rossi R. Detection of S-nitrosothiols in biological fluids: a comparison among the most widely applied methodologies. J Chromatogr B Analyt Technol Biomed Life Sci 2006; 851:124-39. [PMID: 17035104 DOI: 10.1016/j.jchromb.2006.09.031] [Citation(s) in RCA: 97] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2006] [Revised: 09/15/2006] [Accepted: 09/20/2006] [Indexed: 12/21/2022]
Abstract
Many different methodologies have been applied for the detection of S-nitrosothiols (RSNOs) in human biological fluids. One unsatisfactory outcome of the last 14 years of research focused on this issue is that a general consensus on reference values for physiological RSNO concentration in human blood is still missing. Consequently, both RSNO physiological function and their role in disease have not yet been clarified. Here, a summary of the values measured for RSNOs in erythrocytes, plasma, and other biological fluids is provided, together with a critical review of the most widely used analytical methods. Furthermore, some possible methodological drawbacks, responsible for the highlighted discrepancies, are evidenced.
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Affiliation(s)
- Daniela Giustarini
- Department of Neuroscience, Pharmacology Section, Via A. Moro 4, University of Siena, 53100 Siena, Italy
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Teerlink T. Measurement of asymmetric dimethylarginine in plasma: methodological considerations and clinical relevance. Clin Chem Lab Med 2005; 43:1130-8. [PMID: 16197310 DOI: 10.1515/cclm.2005.197] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Asymmetric dimethylarginine (ADMA) is a potent inhibitor of nitric oxide synthase and is regarded as a novel risk factor for cardiovascular disease. The metabolic pathways of ADMA and homocysteine are strongly intertwined. First, during synthesis of ADMA, two equivalents of homocysteine are formed. Second, homocysteine has been shown to inhibit the ADMA-degrading enzyme dimethylarginine dimethylaminohydrolase. Finally, homocysteine, either directly or by increasing oxidative stress, may promote release of free ADMA by accelerating protein degradation. Currently used techniques for the quantification of ADMA in plasma are mostly based on liquid chromatography with fluorimetric or mass spectrometric detection. Plasma ADMA has a very narrow concentration distribution, with an inter-individual coefficient of variation of approximately 12%, and even slightly elevated ADMA concentrations are associated with increased cardiovascular disease risk. Therefore, to generate useful results in clinical research, high precision of the assay used for the quantification of ADMA assay is a matter of prime importance. Assays with a high coefficient of variation may lead to low statistical power in clinical trials and to a severe underestimation of the strength of associations in epidemiological studies.
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Affiliation(s)
- Tom Teerlink
- Metabolic Laboratory, Department of Clinical Chemistry, VU University Medical Center, Amsterdam, The Netherlands.
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Böger RH, Maas R, Schulze F, Schwedhelm E. Elevated levels of asymmetric dimethylarginine (ADMA) as a marker of cardiovascular disease and mortality. Clin Chem Lab Med 2005; 43:1124-9. [PMID: 16197309 DOI: 10.1515/cclm.2005.196] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
AbstractThe endothelium plays a crucial role in the maintenance of vascular tone and structure by releasing the endothelium-derived vasoactive mediator, nitric oxide (NO). NO is formed in healthy vascular endothelium from the amino acid precursor L-arginine. Endothelial dysfunction is caused by various cardiovascular risk factors, metabolic diseases, and systemic or local inflammation. One mechanism that explains the occurrence of endothelial dysfunction is the presence of elevated blood levels of asymmetric dimethylarginine (ADMA) – an L-arginine analogue that inhibits NO formation and thereby can impair vascular function. Accumulating evidence from prospective clinical studies suggests that elevated plasma or serum levels of ADMA are associated with an increased risk of major adverse cardiovascular events. This article gives an updated overview of the currently available literature on ADMA and cardiovascular disease from prospective clinical trials. Recently, advances have been made in the development of analytical methods that are reliable and fast enough to allow determination of ADMA in clinical routine.
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Affiliation(s)
- Rainer H Böger
- Clinical Pharmacology Unit, Institute of Experimental and Clinical Pharmacology, University Hospital Hamburg-Eppendorf, Hamburg, Germany.
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