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Das S, Das P, Maity S, Ghosh P, Dutta A. Mechanochemical reaction of ninhydrin with aromatics, enols and amines: Synthesis, crystal structure and supramolecular self-assembly of cyclic and acyclic adducts. RESULTS IN CHEMISTRY 2023. [DOI: 10.1016/j.rechem.2022.100713] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
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Sotgia S, Berlinguer F, Porcu C, Pasciu V, Molle G, Dattena M, Gallus M, Bassu S, Mangoni AA, Carru C, Zinellu A. Plasma homoarginine concentrations in ewe's pregnancy and association with the number of fetuses. Res Vet Sci 2021; 144:175-180. [PMID: 34823870 DOI: 10.1016/j.rvsc.2021.11.012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Revised: 08/28/2021] [Accepted: 11/16/2021] [Indexed: 11/17/2022]
Abstract
A striking increase in homoarginine concentrations, about more than 100-fold that observed in humans, was recently reported during pregnancy in a nutritionally induced model of intra-uterine growth restriction in ewes. To determine whether this phenomenon is at least partially related to the nutritional regimen, estrus synchronization, or analytical method, thirty-four one-year-old primiparous, non-synchronized, and well-fed Sarda breed ewes were exposed to fertile rams allowing those who came into estrus to naturally mate. Plasma arginine, homoarginine, asymmetric dimethylarginine, symmetric dimethylarginine, mono methylarginine, and citrulline concentrations were measured in each sample using LC-MS/MS. Homoarginine concentrations showed a 44-fold variation between the highest and the lowest values while the fluctuations of arginine and its analogues and metabolites were much smaller, between 1.1 and 1.6-fold. Repeated-measures correlation analysis showed a significant negative correlation between homoarginine/arginine and arginine/asymmetric dimethylarginine ratios (Rm = -0.40; P < 0.000001). Furthermore, median homoarginine concentrations significantly increased with the number of fetuses. The marked increase in homoarginine concentrations with advancing gestational age is genuine and independent of mating, feeding, diet, and hormone treatment. The higher homoarginine concentrations found in ewes bearing multiple fetuses suggest the presence of a physiological link between this arginine analog and energy metabolism in pregnancy that warrants further investigation.
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Affiliation(s)
- Salvatore Sotgia
- Department of Biomedical Sciences, School of Medicine, University of Sassari, Sassari, Italy.
| | | | - Christian Porcu
- Department of Veterinary Medicine, University of Sassari, Sassari, Italy
| | - Valeria Pasciu
- Department of Veterinary Medicine, University of Sassari, Sassari, Italy
| | | | | | | | - Stefania Bassu
- Department of Biomedical Sciences, School of Medicine, University of Sassari, Sassari, Italy
| | - Arduino A Mangoni
- Discipline of Clinical Pharmacology, College of Medicine and Public Health, Flinders University and Flinders Medical Centre, Adelaide, Australia
| | - Ciriaco Carru
- Department of Biomedical Sciences, School of Medicine, University of Sassari, Sassari, Italy
| | - Angelo Zinellu
- Department of Biomedical Sciences, School of Medicine, University of Sassari, Sassari, Italy
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Sotgia S, Zinellu A, Paliogiannis P, Pinna GA, Mangoni AA, Milanesi L, Carru C. A diethylpyrocarbonate-based derivatization method for the LC-MS/MS measurement of plasma arginine and its chemically related metabolites and analogs. Clin Chim Acta 2019; 492:29-36. [PMID: 30731087 DOI: 10.1016/j.cca.2019.02.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2018] [Accepted: 02/04/2019] [Indexed: 12/29/2022]
Abstract
BACKGROUND Changes in NO metabolism correlate with cardiovascular risk factors and are associated with endothelial dysfunction. NO availability is regulated by nitric oxide synthase (NOS) and arginine and some chemically related metabolites and analogs have the capacity to alter NOS activity. Hence the need for analytical methods for the simultaneous assessment of these analytes. METHODS Analytes (L-arginine (Arg), NG-monomethyl-L-arginine (MMA), L-homoarginine (hArg), asymmetric dimethyl-L-arginine (ADMA), symmetric dimethyl-L-arginine (SDMA), and L-citrulline (CIT)) were isolated from human plasma by thermal coagulation of plasma followed by a derivatization with diethylpyrocarbonate. Carbetoxy derivatives were separated on a C18 reversed-phase column in <10 min using an aqueous solution of 0.4% v/v formic acid and acetonitrile (95:5, v/v) mixture as a mobile phase. Positive electrospray ionization and tandem mass spectrometry in combination with specific multiple reaction monitoring transitions were used for detection of analytes and three deuterated forms of the analytes used as internal standards. RESULTS Intra- and inter-day precision %RSD values ranged between 3 and 5.5% and percentage recoveries were close to 100% for all analytes. Plasma concentrations in 20 healthy male volunteers were 58.62 ± 8.81 μmol/L for Arg, 105.08 ± 21.66 nmol/L for MMA, 1.88 ± 0.57 μmol/L for hArg, 0.612 ± 0.140 μmol/L for ADMA, 0.581 ± 0.172 μmol/L for SDMA, and 28.62 ± 11.60 μmol/L for Cit, respectively. CONCLUSION This LC-MS/MS method provides the capacity to quantify the plasma concentrations of arginine and some of its chemically related metabolites. Sample preparation was simple, inexpensive and effortless. Overall, given the short sample preparation and chromatographic run time, the method may be suitable for the fast and reproducible quantitative determination of the analytes in large clinical trials and routine analysis.
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Affiliation(s)
- Salvatore Sotgia
- Department of Biomedical Sciences, School of Medicine, University of Sassari, Sassari, Italy.
| | - Angelo Zinellu
- Department of Biomedical Sciences, School of Medicine, University of Sassari, Sassari, Italy
| | - Panagiotis Paliogiannis
- Department of Biomedical Sciences, School of Medicine, University of Sassari, Sassari, Italy
| | - Gerard A Pinna
- Department of Chemistry and Pharmacy, University of Sassari, Sassari, Italy
| | - Arduino A Mangoni
- Department of Clinical Pharmacology, College of Medicine and Public Health, Flinders University and Flinders Medical Centre, Adelaide, Australia
| | - Luciano Milanesi
- National Research Council (CNR), Institute for Biomedical Technologies, Segrate, Italy
| | - Ciriaco Carru
- Department of Biomedical Sciences, School of Medicine, University of Sassari, Sassari, Italy; Quality Control Unit, University Hospital of Sassari (AOU-SS), Sassari, Italy
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Hammes M, McGill R, Dhar P, Madhurapantula RS. Asymmetric Dimethylarginine does not Predict Early Access Events in Hemodialysis Patients with Brachiocephalic Fistula Access. ACTA ACUST UNITED AC 2017; 3. [PMID: 29104939 PMCID: PMC5667913 DOI: 10.16966/2380-5498.141] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Background Vascular access for hemodialysis is best provided by an arteriovenous fistula (AVF). AVF fail primarily because of neointimal hyperplasia. Asymmetric dimethlyarginine (ADMA) is a naturally occurring analogue of L-arginine, which is elevated in renal failure and impairs endothelial cell function. ADMA inhibits nitric oxide synthetase, leading to impaired nitric oxide production and contributing to the development of neointimal hyperplasia. ADMA was measured at the time of AVF placement to evaluate associations with access failure. Methods ADMA was measured at the time of brachiocephalic access placement. Patients were followed for up to 12 months with end-points of access thrombosis or venous stenosis. Results Sixty patients with primary brachiocephalic fistulas were included in the study cohort. The median value for ADMA drawn at the time of AVF creation was 3.1 µmol/L. ADMA was not significantly associated with early thrombosis or venous stenosis events (P>0.05). Conclusion Preoperative ADMA levels, as a surrogate for endothelial cell dysfunction and predictor of adverse access event (thrombosis or stenosis), were not associated with subsequent access events Future studies that identify markers of endothelial cell dysfunction are warranted.
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Affiliation(s)
- Mary Hammes
- Department of Medicine, Section of Nephrology, University of Chicago, Chicago, IL
| | - Rita McGill
- Department of Medicine, Section of Nephrology, University of Chicago, Chicago, IL
| | - Promila Dhar
- Department of Biomedical Engineering, Illinois Institute of Technology, Chicago, IL
| | - Rama S Madhurapantula
- Department of Biological and Chemical Sciences, Illinois Institute of Technology, Chicago, IL
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Lazich I, Chang A, Watson S, Dhar P, Madhurapantula RS, Hammes M. Morphometric and histological parameters in veins of diabetic patients undergoing brachiocephalic fistula placement. Hemodial Int 2015; 19:490-8. [PMID: 25731584 DOI: 10.1111/hdi.12289] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Diabetic patients with end-stage renal failure have higher rates of arteriovenous failures when compared with nondiabetics. The aim was to compare differences in indicators of vascular remodeling and endothelial dysfunction in veins of patients with or without diabetes at the time of surgical placement. In this prospective observational trial, vein samples were collected from patients when a brachiocephalic fistula was created. Morphometric measurements and extent of fibrosis were determined using Image J software. Histological analysis, for the presence of myofibroblasts and level of endothelial nitric oxide synthase, was performed by immunohistochemical staining and scored in semi-quantitative manner. Asymmetric dimethylarginine was determined at the time of access placement. Comparison of diabetics and nondiabetics was performed using Wilcoxon rank sum and Fisher's exact tests. Eighteen patients were included; 10 were diabetics. There was a significant difference in the measurement of vein area between groups, with diabetic vein samples having larger luminal area of average 832,001.18 μm(2) (317,582.17-3,695,670.36, P = 0.04). The maximal intimal to medial thickness ratio was higher in diabetic vein samples (0.71 vs. 0.24, P = 0.03) along with statistically significant higher maximal intimal thickness (312.12 vs. 115.14 μm, P = 0.03). There is a significant difference in vascular wall remodeling between diabetics and nondiabetics at the level of the cephalic vein at the time of brachiocephalic placement. The unexpected finding of significantly larger luminal area in diabetic veins could be a major factor positively affecting brachiocephalic outcomes in otherwise impaired remodeling in this patient population.
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Affiliation(s)
- Ivana Lazich
- Department of Medicine, Section of Nephrology, University of Chicago, Chicago, Illinois, USA
| | - Anthony Chang
- Department of Pathology, University of Chicago, Chicago, Illinois, USA
| | - Sydeaka Watson
- Department of Health Studies, Biostatistics Laboratory, University of Chicago, Chicago, Illinois, USA
| | - Promila Dhar
- Department of Biomedical Engineering, Illinois Institute of Technology, Chicago, Illinois, USA
| | - Rama S Madhurapantula
- Department of Biological and Chemical Sciences, Illinois Institute of Technology, Chicago, Illinois, USA
| | - Mary Hammes
- Department of Medicine, Section of Nephrology, University of Chicago, Chicago, Illinois, USA
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Liquid chromatography coupled to on-line post column derivatization for the determination of organic compounds: A review on instrumentation and chemistries. Anal Chim Acta 2013; 798:1-24. [DOI: 10.1016/j.aca.2013.07.032] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2013] [Revised: 07/07/2013] [Accepted: 07/11/2013] [Indexed: 11/23/2022]
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Zinellu A, Sotgia S, Deiana L, Carru C. Quantification of arginine and dimethylated arginines in human plasma by field-amplified sample injection capillary electrophoresis UV detection. Methods Mol Biol 2013; 984:131-138. [PMID: 23386341 DOI: 10.1007/978-1-62703-296-4_10] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
We report a capillary electrophoresis method by field-amplified sample injection (FASI) for the separation and detection of free plasma arginine and dimethylated arginines. Protein elimination from plasma was performed by acetonitrile/ammonia precipitation. Supernatants were dried, reswollen in water, and directly injected on capillary without complex cleanup by solid-phase extraction and/or tedious sample derivatization procedures. Analytes were baseline-separated within 22 min by using 50 mmol/L Tris phosphate pH 2.3 as running buffer. Due to the stacking effects of electrokinetic injection, it is possible to perform a considerable on-line preconcentration of the analytes before running the electrophoresis. This procedure allows to reach a detection limit in real sample of 10 nmol/L for dimethylated arginines and 20 nmol/L for arginine. Recovery of plasma ADMA was 99-104 % and inter-day CV was less than 3 %.
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Affiliation(s)
- Angelo Zinellu
- Department Biomedical Sciences, University of Sassari, Sassari, Italy.
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Hui Y, Wong M, Kim JO, Love J, Ansley DM, Chen DDY. A new derivatization method coupled with LC-MS/MS to enable baseline separation and quantification of dimethylarginines in human plasma from patients to receive on-pump CABG surgery. Electrophoresis 2012; 33:1911-20. [PMID: 22740479 DOI: 10.1002/elps.201100536] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Asymmetric dimethylarginine (ADMA) is an inhibitor of nitric oxide synthase and a risk factor for cardiovascular events. We have developed a new derivatization method to enable baseline separation of the regio-isomers, ADMA, and symmetric dimethylarginine (SDMA), within 15 min on a C18 reverse phase column. Reacting naphthalene-2,3-dicarboxaldehyde with ADMA and SDMA in the presence of 2-mercaptoethanol produces corresponding 2,3-dihydro-benzo[f]isoindol-1-ones that are more stable than previously reported ortho-phthaldialdehyde and 2-mercaptoethanol derivatives. LC-MS/MS quantitation of these derivatives can be used to determine ADMA and SDMA concentrations in the plasma of patients to receive on-pump coronary artery bypass grafting (CABG) surgery. The LOD, LOQ and lower LOQ (LLOQ) of this method were determined to be 2.6, 8.7, and 25 nM for ADMA, and 2.5, 8.3, and 25 nM for SDMA, respectively, with consumption of only 50 μL of plasma. The relative standard deviations and relative errors of the intraday and interday determinations, as measurements of reproducibility and accuracy, are all within 15%. The ADMA and SDMA concentrations in patient plasma are 298.1 ± 11.2 nM (mean ± S.E.M., n = 123) and 457.7 ± 19.8 nM (mean ± S.E.M., n = 123), respectively. Upon unblinding of our clinical trial, these predetermined values might explain patient clinical outcomes associated with on-pump CABG surgery, as ADMA is known to inhibit nitric oxide production. Furthermore, this derivatization reaction in conjunction with LC-MS/MS analysis may open a venue to explore alternative chemical labeling modes for LC-MS/MS applications, such as analysis of other amino acids, metabolites, and peptides containing primary amine group(s).
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Affiliation(s)
- Yu Hui
- Department of Chemistry, University of British Colombia, Vancouver, BC, Canada
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Li G, Zhang X, You J, Song C, Sun Z, Xia L, Suo Y. Highly sensitive and selective pre-column derivatization high-performance liquid chromatography approach for rapid determination of triterpenes oleanolic and ursolic acids and application to Swertia species: optimization of triterpenic acids extraction and pre-column derivatization using response surface methodology. Anal Chim Acta 2011; 688:208-18. [PMID: 21334488 DOI: 10.1016/j.aca.2011.01.010] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2010] [Revised: 12/22/2010] [Accepted: 01/12/2011] [Indexed: 11/20/2022]
Abstract
Oleanolic acid (OA) and ursolic acid (UA) are the ubiquitous triterpenic acids in plant kingdom and have multiple biological effects. In the present study, a highly sensitive and selective method using a dual-sensitive probe 2-(5-benzoacridine)ethyl-p-toluenesulfonate (BAETS) as pre-column labeling reagent has been developed for rapid determination of the triterpenes OA and UA by HPLC with fluorescence detection (FLD) and online mass spectrometry identification. Response surface methodology as an efficient tool was employed to optimize the ultrasonic-assisted extraction of triterpenic acids from Swertia plants and the pre-column derivatization reaction, respectively, which ensured the highest triterpenic acids recoveries within the shortest extraction time and the sufficient labeling of the analyzed components. Fast separation of the isomers OA and UA could be achieved on a Hypersil BDS C8 column within 7 min. Both of OA and UA gave the good correlation coefficients of 0.9999. This developed method offered the satisfactory detection limits of 1.10 and 1.30 ng mL(-1) for UA and OA, respectively. When applied to Swertia species, it showed good reproducibility.
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Affiliation(s)
- Guoliang Li
- Northwest Plateau Institute of Biology, Chinese Academy of Sciences, Xining, 810001, PR China
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Saigusa D, Takahashi M, Kanemitsu Y, Ishida A, Abe T, Yamakuni T, Suzuki N, Tomioka Y. Determination of Asymmetric Dimethylarginine and Symmetric Dimethylarginine in Biological Samples of Mice Using LC/MS/MS. ACTA ACUST UNITED AC 2011. [DOI: 10.4236/ajac.2011.23038] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Improved method for plasma ADMA, SDMA, and arginine quantification by field-amplified sample injection capillary electrophoresis UV detection. Anal Bioanal Chem 2010; 399:1815-21. [PMID: 21181467 DOI: 10.1007/s00216-010-4580-0] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2010] [Revised: 12/01/2010] [Accepted: 12/02/2010] [Indexed: 10/18/2022]
Abstract
Here, we describe an easy field-amplified sample injection capillary electrophoresis method with UV detection for the separation and detection of free plasma arginine and dimethylated arginines. The analytes were baseline-separated within 22 min by using 50 mmol/L Tris phosphate pH 2.3 as running buffer. The plasma samples were treated with acetonitrile/ammonia for protein elimination, the supernatants were dried, re-swollen in water and directly injected in the capillary without complex cleanup by solid phase extraction and/or tedious sample derivatization procedures. Due to the stacking effects of the electrokinetic injection, it was possible to operate a consistent on-line pre-concentration of the analytes before running the electrophoresis. This procedure allowed to reach a detection limit in the real sample of 10 nmol/L for dimethylated arginines and 20 nmol/L for arginine, thus improving about threefold our previous method, that required a more complicated pre-analytical procedure to concentrate samples. The recovery of plasma ADMA was 99-104% and inter-day CV was less than 3%. The assay performance was evaluated measuring the levels of arginine and its dimethyl derivatives in 50 subjects. The statistical tests for the methods comparison suggest that the data obtained by our new method and by our previous CE assay are similar.
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Determination of trace amino acids in human serum by a selective and sensitive pre-column derivatization method using HPLC-FLD-MS/MS and derivatization optimization by response surface methodology. Amino Acids 2010; 40:1185-93. [PMID: 20844907 DOI: 10.1007/s00726-010-0742-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2010] [Accepted: 08/31/2010] [Indexed: 10/19/2022]
Abstract
Analysis of trace amino acids (AA) in physiological fluids has received more attention, because the analysis of these compounds could provide fundamental and important information for medical, biological, and clinical researches. More accurate method for the determination of those compounds is highly desirable and valuable. In the present study, we developed a selective and sensitive method for trace AA determination in biological samples using 2-[2-(7H-dibenzo [a,g]carbazol-7-yl)-ethoxy] ethyl chloroformate (DBCEC) as labeling reagent by HPLC-FLD-MS/MS. Response surface methodology (RSM) was first employed to optimize the derivatization reaction between DBCEC and AA. Compared with traditional single-factor design, RSM was capable of lessening laborious, time and reagents consumption. The complete derivatization can be achieved within 6.3 min at room temperature. In conjunction with a gradient elution, a baseline resolution of 20 AA containing acidic, neutral, and basic AA was achieved on a reversed-phase Hypersil BDS C(18) column. This method showed excellent reproducibility and correlation coefficient, and offered the exciting detection limits of 0.19-1.17 fmol/μL. The developed method was successfully applied to determinate AA in human serum. The sensitive and prognostic index of serum AA for liver diseases has also been discussed.
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High fat feeding and dietary L-arginine supplementation differentially regulate gene expression in rat white adipose tissue. Amino Acids 2009; 37:187-98. [PMID: 19212806 DOI: 10.1007/s00726-009-0246-7] [Citation(s) in RCA: 103] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2009] [Accepted: 01/20/2009] [Indexed: 12/17/2022]
Abstract
Dietary L-arginine (Arg) supplementation reduces white-fat gain in diet-induced obese rats but the underlying mechanisms are unknown. This study tested the hypothesis that Arg treatment affects expression of genes related to lipid metabolism in adipose tissue. Four-week-old male Sprague-Dawley rats were fed a low-fat (LF) or high-fat (HF) diet for 15 weeks. Thereafter, lean or obese rats continued to be fed their same respective diets and received drinking water containing 1.51% Arg-HCl or 2.55% L: -alanine (isonitrogenous control). After 12 weeks of Arg supplementation, rats were euthanized to obtain retroperitoneal adipose tissue for analyzing global changes in gene expression by microarray. The results were confirmed by RT-PCR analysis. HF feeding decreased mRNA levels for lipogenic enzymes, AMP-activated protein kinase, glucose transporters, heme oxygenase 3, glutathione synthetase, superoxide dismutase 3, peroxiredoxin 5, glutathione peroxidase 3, and stress-induced protein, while increasing expression of carboxypeptidase-A, peroxisome proliferator activated receptor (PPAR)-alpha, caspase 2, caveolin 3, and diacylglycerol kinase. In contrast, Arg supplementation reduced mRNA levels for fatty acid binding protein 1, glycogenin, protein phosphates 1B, caspases 1 and 2, and hepatic lipase, but increased expression of PPARgamma, heme oxygenase 3, glutathione synthetase, insulin-like growth factor II, sphingosine-1-phosphate receptor, and stress-induced protein. Biochemical analysis revealed oxidative stress in white adipose tissue of HF-fed rats, which was prevented by Arg supplementation. Collectively, these results indicate that HF diet and Arg supplementation differentially regulate gene expression to affect energy-substrate oxidation, redox state, fat accretion, and adipocyte differentiation in adipose tissue. Our findings provide a molecular mechanism to explain a beneficial effect of Arg on ameliorating diet-induced obesity in mammals.
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Abstract
Obesity and type-II diabetes are growing major health issues worldwide. They are the leading risk factors for vascular insulin resistance, which plays an important role in the pathogenesis of cardiovascular disease, the leading cause of death in developed nations. Recent studies have shown that reduced synthesis of nitric oxide (NO; a major vasodilator) from L-arginine in endothelial cells is a major factor contributing to the impaired action of insulin in the vasculature of obese and diabetic subjects. The decreased NO generation results from a deficiency of (6R)-5,6,7,8-tetrahydrobiopterin [BH4; an essential cofactor for NO synthase (NOS)], as well as increased generation of glucosamine (an inhibitor of the pentose cycle for the production of NADPH, another cofactor for NOS) from glucose and L-glutamine. Accordingly, endothelial dysfunction can be prevented by (1) enhancement of BH4 synthesis through supplementation of its precursor (sepiapterin) via the salvage pathway; (2) transfer of the gene for GTP cyclohydrolase-I (the first and key regulatory enzyme for de novo synthesis of BH4); or (3) dietary supplementation of L-arginine (which stimulates GTP cyclohydrolase-I expression and inhibits hexosamine production). Modulation of the arginine-NO pathway by BH4 and arginine is beneficial for ameliorating vascular insulin resistance in obesity and diabetes.
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Affiliation(s)
- Guoyao Wu
- Department of Animal Science and Faculty of Nutrition, Texas A&M University, College Station, TX 77843-2471, USA.
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Wu G, Bazer FW, Davis TA, Kim SW, Li P, Marc Rhoads J, Carey Satterfield M, Smith SB, Spencer TE, Yin Y. Arginine metabolism and nutrition in growth, health and disease. Amino Acids 2008; 37:153-68. [PMID: 19030957 DOI: 10.1007/s00726-008-0210-y] [Citation(s) in RCA: 818] [Impact Index Per Article: 51.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2008] [Accepted: 11/05/2008] [Indexed: 12/11/2022]
Abstract
L-Arginine (Arg) is synthesised from glutamine, glutamate, and proline via the intestinal-renal axis in humans and most other mammals (including pigs, sheep and rats). Arg degradation occurs via multiple pathways that are initiated by arginase, nitric-oxide synthase, Arg:glycine amidinotransferase, and Arg decarboxylase. These pathways produce nitric oxide, polyamines, proline, glutamate, creatine, and agmatine with each having enormous biological importance. Arg is also required for the detoxification of ammonia, which is an extremely toxic substance for the central nervous system. There is compelling evidence that Arg regulates interorgan metabolism of energy substrates and the function of multiple organs. The results of both experimental and clinical studies indicate that Arg is a nutritionally essential amino acid (AA) for spermatogenesis, embryonic survival, fetal and neonatal growth, as well as maintenance of vascular tone and hemodynamics. Moreover, a growing body of evidence clearly indicates that dietary supplementation or intravenous administration of Arg is beneficial in improving reproductive, cardiovascular, pulmonary, renal, gastrointestinal, liver and immune functions, as well as facilitating wound healing, enhancing insulin sensitivity, and maintaining tissue integrity. Additionally, Arg or L-citrulline may provide novel and effective therapies for obesity, diabetes, and the metabolic syndrome. The effect of Arg in treating many developmental and health problems is unique among AAs, and offers great promise for improved health and wellbeing of humans and animals.
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Affiliation(s)
- Guoyao Wu
- Department of Animal Science, Texas A&M University, College Station, TX 77843, USA.
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Sotgia S, Zinellu A, Pisanu E, Pinna GA, Deiana L, Carru C. Enantiomeric reversed-phase high-performance liquid chromatography resolution of d-/l-penicillamine after spirocyclization with ninhydrin and by using copper(II)-l-proline complex as a chiral selector in the mobile phase. J Chromatogr A 2008; 1205:90-3. [DOI: 10.1016/j.chroma.2008.08.021] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2008] [Revised: 08/04/2008] [Accepted: 08/07/2008] [Indexed: 11/29/2022]
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