1
|
Schwedhelm E, Cordts K, Moritz E, Wesemann R, Choe CU, Böger R, Ittermann T, Dörr M, Friedrich N, Bahls M. Reference Interval for Serum L-Homoarginine Determined with Enzyme-Linked Immunosorbent Assay in the Population-Based Study of Health in Pomerania. J Appl Lab Med 2022; 7:1272-1282. [DOI: 10.1093/jalm/jfac074] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Accepted: 07/12/2022] [Indexed: 11/12/2022]
Abstract
Abstract
Background
Low levels of the endogenous amino acid L-homoarginine are a risk factor for cardiovascular morbidity and mortality. For individual risk prediction, commercially available test systems are mandatory. This study aims at formulating sex- and age-specific reference intervals of serum L-homoarginine determined with an ELISA.
Methods
We determined reference intervals for serum L-homoarginine stratified by age and sex in a sample of 1285 healthy participants of the Study of Health in Pomerania (SHIP)-TREND cohort after exclusion of participants with cardiovascular diseases, diabetes mellitus, hypertension, metabolic syndrome, elevated liver enzymes, chronic kidney disease stages III or IV, or body mass index >25 kg/m2. Serum L-homoarginine was determined applying a commercially available ELISA.
Results
The reference cohort included 836 women (median age 41, 25th and 75th percentiles are 32 and 50 years) and 449 men (median age 38, 25th, and 75th percentiles are 30 and 49 years). The median serum concentration of L-homoarginine was 1.93 (25th 1.49; 75th 2.60) µmol/L in women and 2.02 (25th 1.63; 75th 2.61) µmol/L in men (P = 0.04). The reference intervals (2.5th to 97.5th percentile) were 0.89–5.29 µmol/L for women and 1.09–3.76 µmol/L for men. The L-homoarginine serum concentration declined over age decades in both sexes and a notable interaction with sex hormone intake in women was observed.
Conclusions
The novelty of our study is that we determined reference intervals specific for the L-isomer being lower than those previously reported for homoarginine in SHIP and thus might be helpful in identifying individuals suitable for oral L-homoarginine supplementation.
Collapse
Affiliation(s)
- Edzard Schwedhelm
- Institute of Clinical Pharmacology and Toxicology, University Medical Center Hamburg-Eppendorf , Hamburg , Germany
- German Center for Cardiovascular Research (DZHK), Partner Site Hamburg/Kiel/Lübeck , Hamburg , Germany
| | - Kathrin Cordts
- Institute of Clinical Pharmacology and Toxicology, University Medical Center Hamburg-Eppendorf , Hamburg , Germany
| | - Eileen Moritz
- Institute of Pharmacology, University Medicine Greifswald , Greifswald , Germany
- German Center for Cardiovascular Research (DZHK), Partner Site Greifswald , Greifswald , Germany
| | | | - Chi un Choe
- Department of Neurology, University Medical Center Hamburg-Eppendorf , Hamburg , Germany
| | - Rainer Böger
- Institute of Clinical Pharmacology and Toxicology, University Medical Center Hamburg-Eppendorf , Hamburg , Germany
| | - Till Ittermann
- German Center for Cardiovascular Research (DZHK), Partner Site Greifswald , Greifswald , Germany
- Institute for Community Medicine, University Medicine Greifswald , Greifswald , Germany
| | - Marcus Dörr
- German Center for Cardiovascular Research (DZHK), Partner Site Greifswald , Greifswald , Germany
- Department of Internal Medicine B, University Medicine Greifswald , Greifswald , Germany
| | - Nele Friedrich
- German Center for Cardiovascular Research (DZHK), Partner Site Greifswald , Greifswald , Germany
- Institute of Clinical Chemistry and Laboratory Medicine, University Medicine Greifswald , Greifswald , Germany
| | - Martin Bahls
- German Center for Cardiovascular Research (DZHK), Partner Site Greifswald , Greifswald , Germany
- Department of Internal Medicine B, University Medicine Greifswald , Greifswald , Germany
| |
Collapse
|
2
|
Kleist CJ, Choe CU, Atzler D, Schönhoff M, Böger R, Schwedhelm E, Wicha SG. Population kinetics of homoarginine and optimized supplementation for cardiovascular risk reduction. Amino Acids 2022; 54:889-896. [PMID: 35618975 PMCID: PMC9213336 DOI: 10.1007/s00726-022-03169-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Accepted: 05/01/2022] [Indexed: 11/24/2022]
Abstract
Homoarginine is an endogenous amino acid whose levels are reduced in patients with renal, cardio- and cerebrovascular disease. Moreover, low homoarginine concentrations independently predict morbidity and mortality in these patients. Besides endogenous synthesis, homoarginine is also a constituent of the human diet. The objective of the present study was to analyze the kinetics of orally supplemented homoarginine in human plasma by means of a pharmacometric approach. We developed a pharmacometric model to evaluate different dosing regimens, especially the regimen of 125 mg once weekly, based on a previous clinical study (n = 20). The model was adapted to account for differences in baseline homoarginine plasma concentrations between healthy and diseased individuals. A novel dosing regimen of 25 mg once daily led to higher attainment of homoarginine reference concentrations using clinical trial simulations. With 25 mg/day, the trough concentration of only 6% of the older and 3.8% of the younger population was predicted to be below the target concentration of 2.0–4.1 µmol/L. In synopsis, the new dosing regimen recapitulates the kinetics of homoarginine in healthy individuals optimally.
Collapse
Affiliation(s)
- Christine J Kleist
- Department of Clinical Pharmacy, Institute of Pharmacy, University of Hamburg, Bundesstraße 45, 20146, Hamburg, Germany
| | - Chi-Un Choe
- Department of Neurology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Dorothee Atzler
- Institute for Cardiovascular Prevention, Ludwig-Maximilians-Universität, Munich, Germany.,German Centre for Cardiovascular Research (DZHK), Partner Site Munich Heart Alliance, Munich, Germany.,Walther Straub Institute of Pharmacology and Toxicology, Ludwig-Maximilians-Universität, Munich, Germany.,Institute of Clinical Pharmacology and Toxicology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Mirjam Schönhoff
- Institute of Clinical Pharmacology and Toxicology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Rainer Böger
- Institute of Clinical Pharmacology and Toxicology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,German Centre for Cardiovascular Research (DZHK), Partner Site Hamburg/Kiel/Lübeck, Hamburg, Germany
| | - Edzard Schwedhelm
- Institute of Clinical Pharmacology and Toxicology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,German Centre for Cardiovascular Research (DZHK), Partner Site Hamburg/Kiel/Lübeck, Hamburg, Germany
| | - Sebastian G Wicha
- Department of Clinical Pharmacy, Institute of Pharmacy, University of Hamburg, Bundesstraße 45, 20146, Hamburg, Germany.
| |
Collapse
|
3
|
Surrer DB, Fromm MF, Maas R, König J. L-Arginine and Cardioactive Arginine Derivatives as Substrates and Inhibitors of Human and Mouse NaCT/Nact. Metabolites 2022; 12:metabo12040273. [PMID: 35448460 PMCID: PMC9026504 DOI: 10.3390/metabo12040273] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Revised: 03/17/2022] [Accepted: 03/19/2022] [Indexed: 01/25/2023] Open
Abstract
The uptake transporter NaCT (gene symbol SLC13A5) is expressed in liver and brain and important for energy metabolism and brain development. Substrates include tricarboxylic acid cycle intermediates, e.g., citrate and succinate. To gain insights into the substrate spectrum of NaCT, we tested whether arginine and the cardioactive L-arginine metabolites asymmetric dimethylarginine (ADMA) and L-homoarginine are also transported by human and mouse NaCT/Nact. Using HEK293 cells overexpressing human or mouse NaCT/Nact we characterized these substances as substrates. Furthermore, inhibition studies were performed using the arginine derivative symmetric dimethylarginine (SDMA), the NaCT transport inhibitor BI01383298, and the prototypic substrate citrate. Arginine and the derivatives ADMA and L-homoarginine were identified as substrates of human and mouse NaCT. Transport of arginine and derivatives mediated by human and mouse NaCT were dose-dependently inhibited by SDMA. Whereas BI01383298 inhibited only human NaCT-mediated citrate uptake, it inhibits the uptake of arginine and derivatives mediated by both human NaCT and mouse Nact. In contrast, the prototypic substrate citrate inhibited the transport of arginine and derivatives mediated only by human NaCT. These results demonstrate a so far unknown link between NaCT/Nact and L-arginine and its cardiovascular important derivatives.
Collapse
Affiliation(s)
| | | | | | - Jörg König
- Correspondence: ; Tel.: +49-9131-8522077
| |
Collapse
|
4
|
Serum Metabolites Responding in a Dose-Dependent Manner to the Intake of a High-Fat Meal in Normal Weight Healthy Men Are Associated with Obesity. Metabolites 2021; 11:metabo11060392. [PMID: 34208710 PMCID: PMC8233812 DOI: 10.3390/metabo11060392] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Revised: 06/11/2021] [Accepted: 06/15/2021] [Indexed: 12/28/2022] Open
Abstract
Although the composition of the human blood metabolome is influenced both by the health status of the organism and its dietary behavior, the interaction between these two factors has been poorly characterized. This study makes use of a previously published randomized controlled crossover acute intervention to investigate whether the blood metabolome of 15 healthy normal weight (NW) and 17 obese (OB) men having ingested three doses (500, 1000, 1500 kcal) of a high-fat (HF) meal can be used to identify metabolites differentiating these two groups. Among the 1024 features showing a postprandial response, measured between 0 h and 6 h, in the NW group, 135 were dose-dependent. Among these 135 features, 52 had fasting values that were significantly different between NW and OB men, and, strikingly, they were all significantly higher in OB men. A subset of the 52 features was identified as amino acids (e.g., branched-chain amino acids) and amino acid derivatives. As the fasting concentration of most of these metabolites has already been associated with metabolic dysfunction, we propose that challenging normal weight healthy subjects with increasing caloric doses of test meals might allow for the identification of new fasting markers associated with obesity.
Collapse
|
5
|
Transport of L-Arginine Related Cardiovascular Risk Markers. J Clin Med 2020; 9:jcm9123975. [PMID: 33302555 PMCID: PMC7764698 DOI: 10.3390/jcm9123975] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Revised: 11/30/2020] [Accepted: 12/01/2020] [Indexed: 12/15/2022] Open
Abstract
L-arginine and its derivatives, asymmetric and symmetric dimethylarginine (ADMA and SDMA) and L-homoarginine, have emerged as cardiovascular biomarkers linked to cardiovascular outcomes and various metabolic and functional pathways such as NO-mediated endothelial function. Cellular uptake and efflux of L-arginine and its derivatives are facilitated by transport proteins. In this respect the cationic amino acid transporters CAT1 and CAT2 (SLC7A1 and SLC7A2) and the system y+L amino acid transporters (SLC7A6 and SLC7A7) have been most extensively investigated, so far, but the number of transporters shown to mediate the transport of L-arginine and its derivatives is constantly increasing. In the present review we assess the growing body of evidence regarding the function, expression, and clinical relevance of these transporters and their possible relation to cardiovascular diseases.
Collapse
|
6
|
Sasani A, Hornig S, Grzybowski R, Cordts K, Hanff E, Tsikas D, Böger R, Gerloff C, Isbrandt D, Neu A, Schwedhelm E, Choe CU. Muscle phenotype of AGAT- and GAMT-deficient mice after simvastatin exposure. Amino Acids 2019; 52:73-85. [DOI: 10.1007/s00726-019-02812-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Accepted: 12/05/2019] [Indexed: 01/03/2023]
|
7
|
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.
Collapse
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
| |
Collapse
|
8
|
Liyanaarachchi G, Mahanama K, Somasiri H, Punyasiri P. Validation of a reversed-phase high-performance liquid chromatographic method for the determination of free amino acids in rice using l-theanine as the internal standard. Food Chem 2018; 240:196-203. [DOI: 10.1016/j.foodchem.2017.07.038] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2017] [Revised: 06/17/2017] [Accepted: 07/10/2017] [Indexed: 10/19/2022]
|
9
|
The biomarker and causal roles of homoarginine in the development of cardiometabolic diseases: an observational and Mendelian randomization analysis. Sci Rep 2017; 7:1130. [PMID: 28442717 PMCID: PMC5430630 DOI: 10.1038/s41598-017-01274-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2016] [Accepted: 03/28/2017] [Indexed: 02/05/2023] Open
Abstract
High L-homoarginine (hArg) levels are directly associated with several risk factors for cardiometabolic diseases whereas low levels predict increased mortality in prospective studies. The biomarker role of hArg in young adults remains unknown. To study the predictive value of hArg in the development of cardiometabolic risk factors and diseases, we utilized data on high-pressure liquid chromatography-measured hArg, cardiovascular risk factors, ultrasound markers of preclinical atherosclerosis and type 2 diabetes from the population-based Young Finns Study involving 2,106 young adults (54.6% females, aged 24–39). We used a Mendelian randomization approach involving tens to hundreds of thousands of individuals to test causal associations. In our 10-year follow-up analysis, hArg served as an independent predictor for future hyperglycaemia (OR 1.31, 95% CI 1.06–1.63) and abdominal obesity (OR 1.60, 95% 1.14–2.30) in men and type 2 diabetes in women (OR 1.55, 95% CI 1.02–2.41). The MR analysis revealed no evidence of causal associations between serum hArg and any of the studied cardiometabolic outcomes. In conclusion, lifetime exposure to higher levels of circulating hArg does not seem to alter cardiometabolic disease risk. Whether hArg could be used as a biomarker for identification of individuals at risk developing cardiometabolic abnormalities merits further investigation.
Collapse
|
10
|
Morris SM. Arginine Metabolism Revisited. J Nutr 2016; 146:2579S-2586S. [PMID: 27934648 DOI: 10.3945/jn.115.226621] [Citation(s) in RCA: 220] [Impact Index Per Article: 27.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2015] [Revised: 01/22/2016] [Accepted: 02/05/2016] [Indexed: 01/20/2023] Open
Abstract
Mammalian arginine metabolism is complex due to the expression of multiple enzymes that utilize arginine as substrate and to interactions or competition between specific enzymes involved in arginine metabolism. Moreover, cells may contain multiple intracellular arginine pools that are not equally accessible to all arginine metabolic enzymes, thus presenting additional challenges to more fully understanding arginine metabolism. At the whole-body level, arginine metabolism ultimately results in the production of a biochemically diverse range of products, including nitric oxide, urea, creatine, polyamines, proline, glutamate, agmatine, and homoarginine. Included in this group of compounds are the methylated arginines (e.g., asymmetric dimethylarginine), which are released upon degradation of proteins containing methylated arginine residues. Changes in arginine concentration also can regulate cellular metabolism and function via a variety of arginine sensors. Although much is known about arginine metabolism, elucidation of the physiologic or pathophysiologic roles for all of the pathways and their metabolites remains an active area of investigation, as exemplified by current findings highlighted in this review.
Collapse
Affiliation(s)
- Sidney M Morris
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA
| |
Collapse
|
11
|
A Novel Pathway for Metabolism of the Cardiovascular Risk Factor Homoarginine by alanine:glyoxylate aminotransferase 2. Sci Rep 2016; 6:35277. [PMID: 27752063 PMCID: PMC5082758 DOI: 10.1038/srep35277] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Accepted: 09/23/2016] [Indexed: 01/06/2023] Open
Abstract
Low plasma concentrations of L-homoarginine are associated with an increased risk of cardiovascular events, while homoarginine supplementation is protective in animal models of metabolic syndrome and stroke. Catabolism of homoarginine is still poorly understood. Based on the recent findings from a Genome Wide Association Study we hypothesized that homoarginine can be metabolized by alanine:glyoxylate aminotransferase 2 (AGXT2). We purified human AGXT2 from tissues of AGXT2 transgenic mice and demonstrated its ability to metabolize homoarginine to 6-guanidino-2-oxocaproic acid (GOCA). After incubation of HepG2 cells overexpressing AGXT2 with isotope-labeled homoarginine-d4 we were able to detect labeled GOCA in the medium. We injected wild type mice with labeled homoarginine and detected labeled GOCA in the plasma. We found that AGXT2 knockout (KO) mice have higher homoarginine and lower GOCA plasma levels as compared to wild type mice, while the reverse was true for AGXT2 transgenic (Tg) mice. In summary, we experimentally proved the presence of a new pathway of homoarginine catabolism – its transamination by AGXT2 with formation of GOCA and demonstrated that endogenous AGXT2 is required for maintenance of homoarginine levels in mice. Our findings may lead to development of novel therapeutic approaches for cardiovascular pathologies associated with homoarginine deficiency.
Collapse
|
12
|
Hou Y, Hu S, Jia S, Nawaratna G, Che D, Wang F, Bazer FW, Wu G. Whole-body synthesis of L-homoarginine in pigs and rats supplemented with L-arginine. Amino Acids 2016; 48:993-1001. [PMID: 26676627 DOI: 10.1007/s00726-015-2145-4] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2015] [Accepted: 11/24/2015] [Indexed: 12/15/2022]
Abstract
Recent studies suggest an important role for L-homoarginine in cardiovascular, hepatic and neurological functions, as well as the regulation of glucose metabolism. However, little is known about whole-body L-homoarginine synthesis or its response to dietary L-arginine intake in animals. Four series of experiments were conducted to determine L-homoarginine synthesis and catabolism in pigs and rats. In Experiment 1, male and female pigs were fed a corn- and soybean meal-based diet supplemented with 0.0-2.42 % L-arginine-HCl. In Experiment 2, male and female rats were fed a casein-based diet, while receiving drinking water containing supplemental L-arginine-HCl to provide 0.0-3.6 g L-arginine/kg body-weight/day. In both experiments, urine collected from the animals for 24 h was analyzed for L-homoarginine and related metabolites. In Experiment 3, pigs and rats received a single oral dose of 1 or 10 mg L-homoarginine/kg body-weight, respectively, and their urine was collected for 24 h for analyses of L-homoarginine and related substances. In Experiment 4, slices of pig and rat tissues (including liver, brain, kidney, heart, and skeletal-muscle) were incubated for 1 h in Krebs-bicarbonate buffer containing 5 or 50 µM L-homoarginine. Our results indicated that: (a) animal tissues did not degrade L-homoarginine in the presence of physiological concentrations of other amino-acids; (b) 95-96 % of orally administered L-homoarginine was recovered in urine; (c) L-homoarginine was quantitatively a minor product of L-arginineg catabolism in the body; and (d) dietary L-arginine supplementation dose-dependently increased whole-body L-homoarginine synthesis. These novel findings provide a new framework for future studies of L-homoarginine metabolism and physiology in animals and humans.
Collapse
Affiliation(s)
- Yongqing Hou
- Hubei Key Laboratory of Animal Nutrition and Feed Science, Hubei Collaborative Innovation Center for Animal Nutrition and Feed Safety,, Wuhan Polytechnic University, Wuhan, 430023, China
- Department of Animal Science, Texas A&M University, College Station, TX, 77843, USA
| | - Shengdi Hu
- Department of Animal Science, Texas A&M University, College Station, TX, 77843, USA
| | - Sichao Jia
- Department of Animal Science, Texas A&M University, College Station, TX, 77843, USA
| | - Gayan Nawaratna
- Department of Animal Science, Texas A&M University, College Station, TX, 77843, USA
| | - Dongsheng Che
- Department of Animal Science, Texas A&M University, College Station, TX, 77843, USA
| | - Fenglai Wang
- Department of Animal Science, Texas A&M University, College Station, TX, 77843, USA
| | - Fuller W Bazer
- Department of Animal Science, Texas A&M University, College Station, TX, 77843, USA
| | - Guoyao Wu
- Hubei Key Laboratory of Animal Nutrition and Feed Science, Hubei Collaborative Innovation Center for Animal Nutrition and Feed Safety,, Wuhan Polytechnic University, Wuhan, 430023, China.
- Department of Animal Science, Texas A&M University, College Station, TX, 77843, USA.
| |
Collapse
|
13
|
Stockebrand M, Hornig S, Neu A, Atzler D, Cordts K, Böger RH, Isbrandt D, Schwedhelm E, Choe CU. Homoarginine supplementation improves blood glucose in diet-induced obese mice. Amino Acids 2015; 47:1921-9. [DOI: 10.1007/s00726-015-2022-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2015] [Accepted: 06/01/2015] [Indexed: 10/23/2022]
|
14
|
Homoarginine in the renal and cardiovascular systems. Amino Acids 2015; 47:1703-13. [DOI: 10.1007/s00726-015-1993-2] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2015] [Accepted: 04/18/2015] [Indexed: 10/23/2022]
|
15
|
Yin J, Ren W, Hou Y, Wu M, Xiao H, Duan J, Zhao Y, Li T, Yin Y, Wu G, Nyachoti CM. Use of homoarginine for measuring true ileal digestibility of amino acids in food protein. Amino Acids 2015; 47:1795-803. [DOI: 10.1007/s00726-015-1958-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2015] [Accepted: 03/06/2015] [Indexed: 10/23/2022]
|
16
|
Possible sources and functions of l-homoarginine in the brain: review of the literature and own findings. Amino Acids 2015; 47:1729-40. [DOI: 10.1007/s00726-015-1960-y] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2015] [Accepted: 03/05/2015] [Indexed: 11/30/2022]
|