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Homoarginine and methylarginines independently predict long-term outcome in patients presenting with suspicion of venous thromboembolism. Sci Rep 2021; 11:9569. [PMID: 33953241 PMCID: PMC8100302 DOI: 10.1038/s41598-021-88986-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Accepted: 04/12/2021] [Indexed: 11/09/2022] Open
Abstract
Endogenous arginine derivatives homoarginine, asymmetric dimethylarginine (ADMA) and symmetric dimethyarginine (SDMA) are independent mortality predictors in atherosclerotic cardiovascular disease (CVD). Our study reports the first analysis, whether homoarginine, ADMA and SDMA predict venous thromboembolism (VTE) recurrence and overall mortality in patients with suspected acute VTE. We assessed serum levels of homoarginine, ADMA and SDMA by LC-MS/MS in 865 individuals from a prospective consecutive cohort of patients with clinical suspicion of VTE. The median follow-up time for mortality was 1196 days. VTE was confirmed by imaging in 418 patients and excluded in 447 patients. Low levels of homoarginine and high levels of ADMA or SDMA independently predicted all-cause mortality after adjustment for sex, age, oral anticoagulants, body mass index, arterial hypertension, diabetes mellitus, smoking, dyslipidemia, chronic heart failure, history of stroke, creatinine and cancer both in patients with VTE and without VTE. Interestingly, none of those parameters was predictive for VTE recurrence. We provide the first report that low circulating levels of homoarginine and high circulating levels of ADMA and SDMA independently predict all-cause mortality in patients with suspected VTE. These parameters might serve as markers of "frailty" and should be considered for future risk stratification approaches in this clinical population. Taking into account that homoarginine supplementation is protective in animal models of CVD and safe in healthy human volunteers, our study provides the basis for future homoarginine supplementation studies in patients with suspected VTE to investigate possible direct protective effects of homoarginine in this population.
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van der Laan T, Boom I, Maliepaard J, Dubbelman AC, Harms AC, Hankemeier T. Data-Independent Acquisition for the Quantification and Identification of Metabolites in Plasma. Metabolites 2020; 10:metabo10120514. [PMID: 33353236 PMCID: PMC7766927 DOI: 10.3390/metabo10120514] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Revised: 12/13/2020] [Accepted: 12/16/2020] [Indexed: 02/06/2023] Open
Abstract
A popular fragmentation technique for non-targeted analysis is called data-independent acquisition (DIA), because it provides fragmentation data for all analytes in a specific mass range. In this work, we demonstrated the strengths and weaknesses of DIA. Two types of chromatography (fractionation/3 min and hydrophilic interaction liquid chromatography (HILIC)/18 min) and three DIA protocols (variable sequential window acquisition of all theoretical mass spectra (SWATH), fixed SWATH and MSALL) were used to evaluate the performance of DIA. Our results show that fast chromatography and MSALL often results in product ion overlap and complex MS/MS spectra, which reduces the quantitative and qualitative power of these DIA protocols. The combination of SWATH and HILIC allowed for the correct identification of 20 metabolites using the NIST library. After SWATH window customization (i.e., variable SWATH), we were able to quantify ten structural isomers with a mean accuracy of 103% (91-113%). The robustness of the variable SWATH and HILIC method was demonstrated by the accurate quantification of these structural isomers in 10 highly diverse blood samples. Since the combination of variable SWATH and HILIC results in good quantitative and qualitative fragmentation data, it is promising for both targeted and untargeted platforms. This should decrease the number of platforms needed in metabolomics and increase the value of a single analysis.
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Rodionov RN, Begmatov H, Jarzebska N, Patel K, Mills MT, Ghani Z, Khakshour D, Tamboli P, Patel MN, Abdalla M, Assaf M, Bornstein SR, Millan JL, Bode-Böger SM, Martens-Lobenhoffer J, Weiss N, Savinova OV. Homoarginine Supplementation Prevents Left Ventricular Dilatation and Preserves Systolic Function in a Model of Coronary Artery Disease. J Am Heart Assoc 2019; 8:e012486. [PMID: 31304837 PMCID: PMC6662144 DOI: 10.1161/jaha.119.012486] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Background Homoarginine (hArg) has been shown to be cardioprotective in a model of ischemic heart failure; however, the mechanism remains unknown. hArg can inhibit tissue‐nonspecific alkaline phosphatase (TNAP), an enzyme that promotes vascular calcification. We hypothesized that hArg will exert beneficial effects by reducing calcification in a mouse model of coronary artery disease associated with TNAP overexpression and hypercholesterolemia. Methods and Results TNAP was overexpressed in the endothelium in mice homozygous for a low‐density lipoprotein receptor mutation (wicked high cholesterol [WHC] allele). WHC and WHC–endothelial TNAP mice received placebo or hArg supplementation (14 mg/L in drinking water) starting at 6 weeks of age simultaneously with an atherogenic diet. Outcomes were compared between the groups after 4 to 5 weeks on treatment. Experiments were performed in males, which presented a study limitation. As expected, WHC–endothelial TNAP mice on the placebo had increased mortality (median survival 27 days, P<0.0001), increased coronary calcium and lipids (P<0.01), increased left ventricular end‐diastolic diameter (P<0.0001), reduced ejection fraction (P<0.05), and increased myocardial fibrosis (P<0.0001) compared with WHC mice. Contrary to our hypothesis, hArg neither inhibited TNAP activity in vivo nor reduced coronary artery calcification and atherosclerosis in WHC–endothelial TNAP mice; however, compared with the placebo, hArg prevented left ventricular dilatation (P<0.01), preserved ejection fraction (P<0.05), and reduced myocardial fibrosis (P<0.001). Conclusions The beneficial effect of hArg supplementation in the setting of calcified coronary artery disease is likely due to its direct protective actions on the myocardial response to the ischemic injury and not to the inhibition of TNAP activity and calcification.
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Affiliation(s)
- Roman N Rodionov
- 1 University Center for Vascular Medicine Technische Universität Dresden Dresden Germany
| | - Hoshimjon Begmatov
- 2 Department of Biomedical Sciences New York Institute of Technology College of Osteopathic Medicine Old Westbury NY
| | - Natalia Jarzebska
- 1 University Center for Vascular Medicine Technische Universität Dresden Dresden Germany.,3 Department of Anesthesiology and Intensive Care Unit Medicine Pulmonary Engineering Group University Hospital Carl Gustav Carus Technische Universität Dresden Dresden Germany
| | - Ketul Patel
- 2 Department of Biomedical Sciences New York Institute of Technology College of Osteopathic Medicine Old Westbury NY
| | - Matthew T Mills
- 2 Department of Biomedical Sciences New York Institute of Technology College of Osteopathic Medicine Old Westbury NY
| | - Zulaikha Ghani
- 2 Department of Biomedical Sciences New York Institute of Technology College of Osteopathic Medicine Old Westbury NY
| | - Doreen Khakshour
- 2 Department of Biomedical Sciences New York Institute of Technology College of Osteopathic Medicine Old Westbury NY
| | - Pankti Tamboli
- 2 Department of Biomedical Sciences New York Institute of Technology College of Osteopathic Medicine Old Westbury NY
| | - Mitul N Patel
- 2 Department of Biomedical Sciences New York Institute of Technology College of Osteopathic Medicine Old Westbury NY
| | - Mirette Abdalla
- 2 Department of Biomedical Sciences New York Institute of Technology College of Osteopathic Medicine Old Westbury NY
| | - Maryann Assaf
- 2 Department of Biomedical Sciences New York Institute of Technology College of Osteopathic Medicine Old Westbury NY
| | - Stefan R Bornstein
- 4 Department of Internal Medicine III University Hospital Carl Gustav Carus Technische Universität Dresden Dresden Germany
| | - Jose Luis Millan
- 5 Human Genetics Program Sanford Burnham Prebys Medical Discovery Institute La Jolla CA
| | | | | | - Norbert Weiss
- 1 University Center for Vascular Medicine Technische Universität Dresden Dresden Germany
| | - Olga V Savinova
- 2 Department of Biomedical Sciences New York Institute of Technology College of Osteopathic Medicine Old Westbury NY
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Pawlak-Chaouch M, Boissière J, Munyaneza D, Tagougui S, Gamelin FX, Cuvelier G, Heyman E, Goossens JF, Descat A, Berthoin S, Aucouturier J. Plasma asymmetric dimethylarginine concentrations are not related to differences in maximal oxygen uptake in endurance trained and untrained men. Exp Physiol 2018; 104:254-263. [PMID: 30561141 DOI: 10.1113/ep087398] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Accepted: 11/19/2018] [Indexed: 12/14/2022]
Abstract
NEW FINDINGS What is the central question of this study? Is there an association of plasma concentration of asymmetric dimethylarginine, which is related to exercise capacity in patients with cardiovascular diseases, with oxygen delivery and subsequently exercise capacity in healthy subjects in the absence of the potentially confounding influence of inflammation and oxidative stress? What is the main finding and its importance? Plasma asymmetric dimethylarginine concentrations are not related to exercise capacity in healthy subjects, while O2 delivery in the working skeletal muscle during the maximal graded-exercise test is not associated with any of the l-arginine analogues. ADMA alone does not play a crucial role in local muscle perfusion and in maintaining exercise capacity. ABSTRACT Asymmetric dimethylarginine (ADMA) is an endogenous inhibitor of nitric oxide (NO) synthesis that could limit oxygen (O2 ) delivery in the working skeletal muscles by altering endothelium-dependent vasodilatation. Exercise capacity is associated with plasma ADMA concentrations in patients with cardiovascular diseases, but this issue has still not been investigated in healthy subjects. We aimed to determine whether plasma ADMA concentrations were negatively associated with exercise capacity in young healthy male subjects. Ten men with maximal oxygen uptake ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msub><mml:mover><mml:mi>V</mml:mi> <mml:mo>̇</mml:mo></mml:mover> <mml:mrow><mml:msub><mml:mi>O</mml:mi> <mml:mn>2</mml:mn></mml:msub> <mml:mi>max</mml:mi> </mml:mrow> </mml:msub> </mml:math> ) > 65 mL kg-1 min-1 were included in the high exercise capacity group (HI-FIT), and 10 men with <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msub><mml:mover><mml:mi>V</mml:mi> <mml:mo>̇</mml:mo></mml:mover> <mml:mrow><mml:msub><mml:mi>O</mml:mi> <mml:mn>2</mml:mn></mml:msub> <mml:mi>max</mml:mi> </mml:mrow> </mml:msub> </mml:math> < 45 mL kg-1 min-1 were included in the low exercise capacity group (LO-FIT). Plasma ADMA and other l-arginine analogue concentrations were measured before and after a maximal graded-exercise test by liquid chromatography-tandem mass spectrometry. Microvascular O2 delivery during exercise was estimated through the pattern from the sigmoid model of muscle deoxygenation in the vastus lateralis measured by near infrared spectroscopy. <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msub><mml:mover><mml:mi>V</mml:mi> <mml:mo>̇</mml:mo></mml:mover> <mml:mrow><mml:msub><mml:mi>O</mml:mi> <mml:mn>2</mml:mn></mml:msub> <mml:mi>max</mml:mi> </mml:mrow> </mml:msub> </mml:math> was 60% higher in the HI-FIT group (median: 70.2 mL kg-1 min-1 ; IQR: 68.0-71.9 mL kg-1 min-1 ) than in the LO-FIT group (median: 43.8 mL kg-1 min-1 ; IQR: 34.8-45.3 mL kg-1 min-1 ). Plasma ADMA concentrations did not differ between the LO-FIT and HI-FIT groups before (0.50 ± 0.06 vs. 0.54 ± 0.07 μmol L-1 , respectively) and after the maximal incremental exercise test (0.49 ± 0.08 vs. 0.55 ± 0.03 μmol L-1 , respectively). There was no significant association of plasma ADMA concentrations with the pattern of local muscle deoxygenation and exercise capacity. Exercise capacity and microvascular O2 delivery are not related to plasma ADMA concentrations in young healthy male subjects. Our findings show that ADMA does not play a crucial role in local muscle perfusion and in maintaining exercise capacity without pathological conditions.
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Affiliation(s)
- Mehdi Pawlak-Chaouch
- University of Lille, University of Artois, University of Littoral Côte, d'Opale, EA 7369 - URePSSS, Pluridisciplinary Research Unit, "Sport, Health and Society", F-59000, Lille, France
| | - Julien Boissière
- University of Lille, University of Artois, University of Littoral Côte, d'Opale, EA 7369 - URePSSS, Pluridisciplinary Research Unit, "Sport, Health and Society", F-59000, Lille, France
| | - Désiré Munyaneza
- University of Lille, University of Artois, University of Littoral Côte, d'Opale, EA 7369 - URePSSS, Pluridisciplinary Research Unit, "Sport, Health and Society", F-59000, Lille, France
| | - Semah Tagougui
- University of Lille, University of Artois, University of Littoral Côte, d'Opale, EA 7369 - URePSSS, Pluridisciplinary Research Unit, "Sport, Health and Society", F-59000, Lille, France.,Montreal Clinical Research Institute (IRCM), Montreal, Canada
| | - François-Xavier Gamelin
- University of Lille, University of Artois, University of Littoral Côte, d'Opale, EA 7369 - URePSSS, Pluridisciplinary Research Unit, "Sport, Health and Society", F-59000, Lille, France
| | - Grégory Cuvelier
- Laboratory of Exercise and Movement, Provincial School of Hainaut (HEPH)-Condorcet, Tournai, Belgium
| | - Elsa Heyman
- University of Lille, University of Artois, University of Littoral Côte, d'Opale, EA 7369 - URePSSS, Pluridisciplinary Research Unit, "Sport, Health and Society", F-59000, Lille, France
| | - Jean-François Goossens
- Center of Mass Spectrometry 'PSM-GRITA', EA 7365, Faculty of Pharmacology, Lille University, Lille, France
| | - Amandine Descat
- Center of Mass Spectrometry 'PSM-GRITA', EA 7365, Faculty of Pharmacology, Lille University, Lille, France
| | - Serge Berthoin
- University of Lille, University of Artois, University of Littoral Côte, d'Opale, EA 7369 - URePSSS, Pluridisciplinary Research Unit, "Sport, Health and Society", F-59000, Lille, France
| | - Julien Aucouturier
- University of Lille, University of Artois, University of Littoral Côte, d'Opale, EA 7369 - URePSSS, Pluridisciplinary Research Unit, "Sport, Health and Society", F-59000, Lille, France
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L-Homoarginine and its AGXT2-metabolite GOCA in chronic kidney disease as markers for clinical status and prognosis. Amino Acids 2018; 50:1347-1356. [PMID: 29982953 DOI: 10.1007/s00726-018-2610-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Accepted: 06/27/2018] [Indexed: 02/07/2023]
Abstract
Plasma concentrations of L-homoarginine (hArg) are an emerging marker for clinical status and prognosis in renal and cardiovascular disease. Lowered hArg concentrations are associated with higher risk for these conditions, although a clear pathophysiological explanation for this association has not been established. Baseline plasma samples of patients with different stages of chronic kidney disease (CKD) (n = 527) were obtained from the CARE FOR HOMe study and were analyzed for hArg and, for the first time, its metabolite 6-guanidino-2-oxocaproic acid (GOCA) by isotope dilution LC-MS/MS methods. GOCA is converted from hArg by the enzyme alanine:glyoxylate aminotransferase 2 (AGXT2), which is also in the focus of current cardiovascular research. hArg levels ranged from 0.20-4.01 µmol/L with a median of 1.42 µmol/L, whereas GOCA levels were 0.08-25.82 nmol/L with a median of 1.45 nmol/L. hArg levels in the highest tertile (≥ 1.71 µmol/L) were associated with significantly lower risk for reaching the renal (hazard ratio 0.369, 95% confidence interval 0.028-0.655) or cardiovascular (HR 0.458, CI 0.295-0.712) endpoints in univariate Cox regression analysis. Inversely, GOCA levels in the highest tertile (≥ 2.13 nmol/L) were associated with increased renal (HR 3.807, CI 1.963-7.381) and cardiovascular (HR 1.611, CI 1.041-2.495) risk. A decreased ratio between hArg and GOCA predicted even more pronounced the risks for renal (HR 0.178, CI 0.087-0.363) and cardiovascular (HR 0.447, CI 0.281-0.709) events. However, adjustment for the confounders eGFR and albuminuria attenuated these findings. A pathophysiological role of an increased activity of AGXT2 in CKD should be evaluated in future clinical studies.
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Xie B, Wang Y, Jones DR, Dey KK, Wang X, Li Y, Cho JH, Shaw TI, Tan H, Peng J. Isotope Labeling-Assisted Evaluation of Hydrophilic and Hydrophobic Liquid Chromatograph-Mass Spectrometry for Metabolomics Profiling. Anal Chem 2018; 90:8538-8545. [PMID: 29883117 DOI: 10.1021/acs.analchem.8b01591] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
High throughput untargeted metabolomics usually relies on complementary liquid chromatography-mass spectrometry (LC-MS) methods to expand the coverage of diverse metabolites, but the integration of those methods is not fully characterized. We systematically investigated the performance of hydrophilic interaction liquid chromatography (HILIC)-MS and nanoflow reverse-phase liquid chromatography (nRPLC)-MS under 8 LC-MS settings, varying stationary phases (HILIC and C18), mobile phases (acidic and basic pH), and MS ionization modes (positive and negative). Whereas nRPLC-MS optimization was previously reported, we found in HILIC-MS (2.1 mm × 150 mm) that the optimal performance was achieved in a 90 min gradient with 100 μL/min flow rate by loading metabolite extracts from 2 mg of cell/tissue samples. Since peak features were highly compromised by contaminants, we used stable isotope labeled yeast to enhance formula identification for comparing different LC-MS conditions. The 8 LC-MS settings enabled the detection of a total of 1050 formulas, among which 78%, 73%, and 62% formulas were recovered by the best combination of 4, 3, and 2 LC-MS settings, respectively. Moreover, these yeast samples were harvested in the presence or absence of nitrogen starvation, enabling quantitative comparisons of altered formulas and metabolite structures, followed by validation with selected synthetic metabolites. The results revealed that nitrogen starvation downregulated amino acid components but upregulated uridine-related metabolism. In summary, this study introduces a thorough evaluation of hydrophilicity and hydrophobicity based LC-MS and provides information for selecting complementary settings to balance throughput and efficiency during metabolomics experiments.
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Separation of the Structural Isomers of Monomethylarginine in Human Plasma by 2-D-HPLC and MS–MS Detection. Chromatographia 2016. [DOI: 10.1007/s10337-016-3197-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Tang DQ, Zou L, Yin XX, Ong CN. HILIC-MS for metabolomics: An attractive and complementary approach to RPLC-MS. MASS SPECTROMETRY REVIEWS 2016; 35:574-600. [PMID: 25284160 DOI: 10.1002/mas.21445] [Citation(s) in RCA: 121] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2014] [Accepted: 07/28/2014] [Indexed: 05/14/2023]
Abstract
Hydrophilic interaction chromatography (HILIC) is an emerging separation mode of liquid chromatography (LC). Using highly hydrophilic stationary phases capable of retaining polar/ionic metabolites, and accompany with high organic content mobile phase that offer readily compatibility with mass spectrometry (MS) has made HILIC an attractive complementary tool to the widely used reverse-phase (RP) chromatographic separations in metabolomic studies. The combination of HILIC and RPLC coupled with an MS detector expands the number of detected analytes and provides more comprehensive metabolite coverage than use of only RP chromatography. This review describes the recent applications of HILIC-MS/MS in metabolomic studies, ranging from amino acids, lipids, nucleotides, organic acids, pharmaceuticals, and metabolites of specific nature. The biological systems investigated include microbials, cultured cell line, plants, herbal medicine, urine, and serum as well as tissues from animals and humans. Owing to its unique capability to measure more-polar biomolecules, the HILIC separation technique would no doubt enhance the comprehensiveness of metabolite detection, and add significant value for metabolomic investigations. © 2014 Wiley Periodicals, Inc. Mass Spec Rev 35:574-600, 2016.
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Affiliation(s)
- Dao-Quan Tang
- Department of Pharmaceutical Analysis, Xuzhou Medical College, Xuzhou, 221044, China
- Jiangsu Key Lab for the study of New Drug and Clinical Pharmacy, Xuzhou Medical College, Yunlong, China
- NUS Environmental Research Inst., National University of Singapore, 5 A Engineering Srive 1, Singapore, 117411, Singapore
| | - Ll Zou
- Saw Swee Hock School of Public Health, National University of Singapore, 16 Medical Drive, Singapore, 117597, Singapore
| | - Xiao-Xing Yin
- Jiangsu Key Lab for the study of New Drug and Clinical Pharmacy, Xuzhou Medical College, Yunlong, China
| | - Choon Nam Ong
- NUS Environmental Research Inst., National University of Singapore, 5 A Engineering Srive 1, Singapore, 117411, Singapore
- Saw Swee Hock School of Public Health, National University of Singapore, 16 Medical Drive, Singapore, 117597, Singapore
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Martens-Lobenhoffer J, Bode-Böger SM, Clement B. First detection and quantification of N(δ)-monomethylarginine, a structural isomer of N(G)-monomethylarginine, in humans using MS(3). Anal Biochem 2015; 493:14-20. [PMID: 26464121 DOI: 10.1016/j.ab.2015.10.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2015] [Revised: 09/30/2015] [Accepted: 10/01/2015] [Indexed: 11/27/2022]
Abstract
The L-arginine metabolites methylated at the guanidino moiety, such as N(G)-monomethyl-L-arginine (LNMMA), asymmetric N(G),N(G)-dimethyl-L-arginine (ADMA), and symmetric N(G),N(G')-dimethyl-L-arginine (SDMA), are long known to be present in human plasma. Far less is known about the structural isomer of LNMMA, N(δ)-monomethyl-L-arginine (δ-MMA). In prior work, it has been detected in yeast proteins, but it has not been investigated in mammalian plasma or cells. In this work, we present a method for the simultaneous and unambiguous quantification of LNMMA and δ-MMA in human plasma that is capable of detecting δ-MMA separately from LNMMA. The method comprises a simple protein precipitation sample preparation, hydrophilic interaction liquid chromatography (HILIC) gradient elution on an unmodified silica column, and triple stage mass spectrometric detection. Stable isotope-labeled D6-SDMA was used as internal standard. The calibration ranges were 25-1000 nmol/L for LNMMA and 5-350 nmol/L for δ-MMA. The intra- and inter-batch precision determinations resulted in relative standard deviations of less than 12% for both compounds with accuracies of less than 6% deviation from the expected values. In a pilot study enrolling 10 healthy volunteers, mean concentrations of 48.0 ± 7.4 nmol/L for LNMMA and 27.4 ± 7.7 nmol/L for δ-MMA were found.
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Affiliation(s)
| | - Stefanie M Bode-Böger
- Institute of Clinical Pharmacology, Otto von Guericke University, 39120 Magdeburg, Germany
| | - Bernd Clement
- Pharmaceutical Institute, Christian Albrechts University, 24118 Kiel, Germany
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Hou Y, Jia S, Nawaratna G, Hu S, Dahanayaka S, Bazer FW, Wu G. Analysis of l-homoarginine in biological samples by HPLC involving precolumn derivatization with o-phthalaldehyde and N-acetyl-l-cysteine. Amino Acids 2015; 47:2005-14. [DOI: 10.1007/s00726-015-1962-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2015] [Accepted: 03/09/2015] [Indexed: 10/23/2022]
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