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Dao HT, Sharma NK, Barekatain R, Kheravii SK, Bradbury EJ, Wu SB, Swick RA. Supplementation of reduced protein diets with l-arginine and l-citrulline for broilers challenged with subclinical necrotic enteritis. 2. Intestinal permeability, microbiota, and short-chain fatty acid production. ANIMAL PRODUCTION SCIENCE 2022. [DOI: 10.1071/an21394] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Dao HT, Sharma NK, Daneshmand A, Kumar A, Bradbury EJ, Wu SB, Swick RA. Supplementation of reduced protein diets with l-arginine and l-citrulline for broilers challenged with subclinical necrotic enteritis. 1. Growth, carcass yield, and intestinal lesion scores. ANIMAL PRODUCTION SCIENCE 2022. [DOI: 10.1071/an21393] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Dao HT, Clay JW, Sharma NK, Bradbury EJ, Swick RA. Effects of L-arginine and L-citrulline supplementation in reduced protein diets on cecal fermentation metabolites of broilers under normal, cyclic warm temperature and necrotic enteritis challenge. Livest Sci 2022. [DOI: 10.1016/j.livsci.2022.104826] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Dao HT, Swick RA. New insights into arginine and arginine-sparing effects of guanidinoacetic acid and citrulline in broiler diets. WORLD POULTRY SCI J 2021. [DOI: 10.1080/00439339.2021.1967708] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- Hiep Thi Dao
- School of Environmental and Rural Science, Faculty of Science, Agriculture, Business and Law, University of New England, Armidale, New South Wales, Australia
- Faculty of Animal Science, Vietnam National University of Agriculture, Hanoi, Vietnam
| | - Robert A. Swick
- School of Environmental and Rural Science, Faculty of Science, Agriculture, Business and Law, University of New England, Armidale, New South Wales, Australia
- Poultry Hub Australia, University of New England, Armidale, New South Wales, Australia
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Ferguson SK, Redinius KM, Harral JW, Pak DI, Swindle DC, Hirai DM, Blackwell JR, Jones AM, Stenmark KR, Buehler PW, Irwin DC. The effect of dietary nitrate supplementation on the speed-duration relationship in mice with sickle cell disease. J Appl Physiol (1985) 2020; 129:474-482. [PMID: 32702277 DOI: 10.1152/japplphysiol.00122.2020] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Sickle cell disease (SCD) causes exercise intolerance likely due to impaired skeletal muscle function and low nitric oxide (NO) bioavailability. Dietary nitrate improves hemodynamic and metabolic control during exercise in humans and animals. The purpose of this investigation was to assess the impact of nitrate supplementation on exercise capacity as measured by the running speed to exercise duration relationship [critical speed (CS)]in mice with SCD. We tested the hypothesis that nitrate supplementation via beetroot juice (BR) would attenuate the exercise intolerance observed in mice with SCD. Ten wild-type (WT) and 18 Berkley sickle-cell mice (BERK) received water (WT: n = 10, BERK: n = 10) or nitrate-rich BR (BERK+BR: n = 8, nitrate dose 1 mmol/kg/day) for 5 days. Following the supplementation period, all mice performed 3-5 constant-speed treadmill tests that resulted in exhaustion within 1.5 to 20 min. Time to exhaustion vs. treadmill speed was fit to a hyperbolic model to determine CS. CS was significantly lower in BERK vs. WT and BERK+BR with no significant difference between WT and BERK+BR (WT: 36.6 ± 1.6, BERK: 23.8 ± 1.5, BERK+BR: 31.1 ± 2.1 m/min, P < 0.05). Exercise tolerance, measured via CS, was significantly lower in BERK mice relative to WT. However, BERK mice receiving 5 days of nitrate supplementation exhibited no difference in exercise tolerance when compared with WT. These results support the potential utility of a dietary nitrate intervention to improve functionality in SCD patients.NEW & NOTEWORTHY Sickle cell disease compromises muscle O2 delivery resulting in exercise intolerance. Dietary nitrate supplementation increases skeletal muscle blood flow during exercise and may improve exercise capacity in a mouse model of sickle cell disease. We investigated the effects of dietary nitrate supplementation on exercise tolerance in a mouse model of sickle cell disease using the treadmill speed-duration relationship (critical speed). Mice with sickle cell disease provided with a dietary nitrate supplement had a critical speed not significantly different from healthy wild-type mice.
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Affiliation(s)
- Scott K Ferguson
- Department of Kinesiology and Exercise Science, College of Natural and Health Sciences, University of Hawaii at Hilo, Hilo, Hawaii.,Cardiovascular and Pulmonary Research Laboratory, Department of Medicine, University of Colorado Denver, Anschutz Medical Campus, Aurora, Colorado
| | - Katherine M Redinius
- Cardiovascular and Pulmonary Research Laboratory, Department of Medicine, University of Colorado Denver, Anschutz Medical Campus, Aurora, Colorado
| | - Julie W Harral
- Cardiovascular and Pulmonary Research Laboratory, Department of Medicine, University of Colorado Denver, Anschutz Medical Campus, Aurora, Colorado
| | - David I Pak
- Cardiovascular and Pulmonary Research Laboratory, Department of Medicine, University of Colorado Denver, Anschutz Medical Campus, Aurora, Colorado
| | - Delaney C Swindle
- Cardiovascular and Pulmonary Research Laboratory, Department of Medicine, University of Colorado Denver, Anschutz Medical Campus, Aurora, Colorado
| | - Daniel M Hirai
- Department of Health and Kinesiology, College of Health and Human Sciences, Purdue University, West Lafayette, Indiana
| | - Jamie R Blackwell
- Department of Sport and Health Sciences, University of Exeter St. Luke's Campus, Exeter, United Kingdom
| | - Andrew M Jones
- Department of Sport and Health Sciences, University of Exeter St. Luke's Campus, Exeter, United Kingdom
| | - Kurt R Stenmark
- Cardiovascular and Pulmonary Research Laboratory, Department of Medicine, University of Colorado Denver, Anschutz Medical Campus, Aurora, Colorado
| | - Paul W Buehler
- Department of Pathology and The Center for Blood Oxygen Transport and Hemostasis, Department of Pediatrics, The University of Maryland School of Medicine, Baltimore, Maryland
| | - David C Irwin
- Cardiovascular and Pulmonary Research Laboratory, Department of Medicine, University of Colorado Denver, Anschutz Medical Campus, Aurora, Colorado
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Abstract
We have entered an era of exploding interest in therapeutics for sickle cell disease. The expansion in our understanding of sickle cell disease pathophysiology has enhanced the range of potential therapeutic targets. From induction of fetal hemoglobin to antiadhesion molecules, we are potentially on the cusp of making life-altering modifications for individuals with sickle cell disease. This disease population cannot afford to let the current momentum wane. Studies exploring combinations of therapies affecting multiple steps in the pathophysiology and exploring novel and clinically relevant outcomes are incumbent.
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Ferguson SK, Harral JW, Pak DI, Redinius KM, Stenmark KR, Schaer DJ, Buehler PW, Irwin DC. Impact of cell-free hemoglobin on contracting skeletal muscle microvascular oxygen pressure dynamics. Nitric Oxide 2018. [PMID: 29526566 DOI: 10.1016/j.niox.2018.03.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Free hemoglobin (Hb) associated with hemolysis extravasates into vascular tissue and depletes nitric oxide (NO), which leads to impaired vascular function and could impair skeletal muscle metabolic control during exercise. We tested the hypothesis that: 1) free Hb would extravasate into skeletal muscle tissue, reducing the contracting skeletal muscle O2 delivery/O2 utilization ratio (microvascular PO2, PO2mv) to a similar extent as that observed following NO synthase (NOS) blockade, and 2) that the Hb scavenging protein haptoglobin (Hp) would prevent Hb extravasation and inhibit these skeletal muscle tissue effects. PO2mv was measured in eight rats (phosphorescence quenching) at rest and during 180 s of electrically induced (1-Hz) twitch spinotrapezius muscle contractions (experiment 1). A second group of seven rats was also used to investigate the effects of Hb + Hp (experiment 2). For both experiments, measurements were made: 1) during control conditions, 2) following a bolus infusion of either Hb (50 mg/kg) or Hb + Hp (50 mg/kg), and 3) following local superfusion of NG-nitro-l-arginine methyl ester (L-NAME; 10 mg/kg). Additional experiments were completed to visualize Hb extravasation into the muscular tissue using Click chemistry techniques. There were no significant differences in the PO2mv observed at rest for any condition in either experiment (p > 0.05 for all). In experiment 1, both Hb and L-NAME reduced the PO2mv significantly during the steady-state of muscle contractions when compared to control conditions with no differences between Hb and L-NAME (control: 24 ± 1, Hb: 21 ± 1, L-NAME: 20 ± 1 mmHg, p < 0.05). In experiment 2, only L-NAME resulted in a significantly lower PO2mv during the steady-state of muscle contractions (control: 25 ± 1, Hb + Hp: 22 ± 2, L-NAME: 18 ± 1 mmHg, p < 0.05). Free Hb lowered the blood-myocyte O2 driving force to a level not significantly different from L-NAME. However, infusing Hb bound to Hp resulted in no significant differences in steady-state PO2mv during muscle contractions when compared to control. Surprisingly, we did not observe Hb accumulation in skeletal muscle tissue. Taken together these data suggests that free Hb impairs O2 delivery/utilization via a NO scavenging effect. Furthermore, the unchanged PO2mv steady-state observed following Hb + Hp further indicates that vascular compartmentalization of Hb by the scavenger protein haptoglobin may improve skeletal muscle metabolic control and potentially exercise tolerance in those afflicted with hemolytic diseases.
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Affiliation(s)
- Scott K Ferguson
- Cardiovascular and Pulmonary Research Group, School of Medicine, University of Colorado, Denver, Aurora, CO, USA.
| | - Julie W Harral
- Cardiovascular and Pulmonary Research Group, School of Medicine, University of Colorado, Denver, Aurora, CO, USA
| | - David I Pak
- Cardiovascular and Pulmonary Research Group, School of Medicine, University of Colorado, Denver, Aurora, CO, USA
| | - Katherine M Redinius
- Cardiovascular and Pulmonary Research Group, School of Medicine, University of Colorado, Denver, Aurora, CO, USA
| | - Kurt R Stenmark
- Cardiovascular and Pulmonary Research Group, School of Medicine, University of Colorado, Denver, Aurora, CO, USA
| | - Dominik J Schaer
- Division of Internal Medicine, University of Zurich, CH-8091 Zurich, Switzerland
| | - Paul W Buehler
- Laboratory of Biochemistry and Vascular Biology, Center for Biologics Evaluation and Research, U.S. Food and Drug Administration, Silver Spring, MD, USA
| | - David C Irwin
- Cardiovascular and Pulmonary Research Group, School of Medicine, University of Colorado, Denver, Aurora, CO, USA
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Wijnands KAP, Meesters DM, van Barneveld KWY, Visschers RGJ, Briedé JJ, Vandendriessche B, van Eijk HMH, Bessems BAFM, van den Hoven N, von Wintersdorff CJH, Brouckaert P, Bouvy ND, Lamers WH, Cauwels A, Poeze M. Citrulline Supplementation Improves Organ Perfusion and Arginine Availability under Conditions with Enhanced Arginase Activity. Nutrients 2015; 7:5217-38. [PMID: 26132994 PMCID: PMC4516994 DOI: 10.3390/nu7075217] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2015] [Revised: 05/15/2015] [Accepted: 06/18/2015] [Indexed: 01/10/2023] Open
Abstract
Enhanced arginase-induced arginine consumption is believed to play a key role in the pathogenesis of sickle cell disease-induced end organ failure. Enhancement of arginine availability with l-arginine supplementation exhibited less consistent results; however, l-citrulline, the precursor of l-arginine, may be a promising alternative. In this study, we determined the effects of l-citrulline compared to l-arginine supplementation on arginine-nitric oxide (NO) metabolism, arginine availability and microcirculation in a murine model with acutely-enhanced arginase activity. The effects were measured in six groups of mice (n = 8 each) injected intraperitoneally with sterile saline or arginase (1000 IE/mouse) with or without being separately injected with l-citrulline or l-arginine 1 h prior to assessment of the microcirculation with side stream dark-field (SDF)-imaging or in vivo NO-production with electron spin resonance (ESR) spectroscopy. Arginase injection caused a decrease in plasma and tissue arginine concentrations. l-arginine and l-citrulline supplementation both enhanced plasma and tissue arginine concentrations in arginase-injected mice. However, only the citrulline supplementation increased NO production and improved microcirculatory flow in arginase-injected mice. In conclusion, the present study provides for the first time in vivo experimental evidence that l-citrulline, and not l-arginine supplementation, improves the end organ microcirculation during conditions with acute arginase-induced arginine deficiency by increasing the NO concentration in tissues.
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Affiliation(s)
- Karolina A P Wijnands
- Department of Surgery, NUTRIM School for Nutrition, Toxicology and Metabolism, Maastricht University Medical Center, Maastricht 6200 MD, The Netherlands.
| | - Dennis M Meesters
- Department of Surgery, NUTRIM School for Nutrition, Toxicology and Metabolism, Maastricht University Medical Center, Maastricht 6200 MD, The Netherlands.
| | - Kevin W Y van Barneveld
- Department of Surgery, NUTRIM School for Nutrition, Toxicology and Metabolism, Maastricht University Medical Center, Maastricht 6200 MD, The Netherlands.
| | - Ruben G J Visschers
- Department of Surgery, NUTRIM School for Nutrition, Toxicology and Metabolism, Maastricht University Medical Center, Maastricht 6200 MD, The Netherlands.
| | - Jacob J Briedé
- Department of Toxicogenomics, GROW School for Oncology and Developmental Biology, Maastricht University Medical Center, Maastricht 6200, The Netherlands.
| | - Benjamin Vandendriessche
- Department of Molecular Biomedical Research, VIB, Ghent B-9000, Belgium.
- Department of Biomedical Molecular Biology, Ghent University, Ghent B-9000, Belgium.
| | - Hans M H van Eijk
- Department of Surgery, NUTRIM School for Nutrition, Toxicology and Metabolism, Maastricht University Medical Center, Maastricht 6200 MD, The Netherlands.
| | - Babs A F M Bessems
- Department of Surgery, NUTRIM School for Nutrition, Toxicology and Metabolism, Maastricht University Medical Center, Maastricht 6200 MD, The Netherlands.
| | - Nadine van den Hoven
- Department of Surgery, NUTRIM School for Nutrition, Toxicology and Metabolism, Maastricht University Medical Center, Maastricht 6200 MD, The Netherlands.
| | - Christian J H von Wintersdorff
- Department of Surgery, NUTRIM School for Nutrition, Toxicology and Metabolism, Maastricht University Medical Center, Maastricht 6200 MD, The Netherlands.
| | - Peter Brouckaert
- Department of Molecular Biomedical Research, VIB, Ghent B-9000, Belgium.
- Department of Biomedical Molecular Biology, Ghent University, Ghent B-9000, Belgium.
| | - Nicole D Bouvy
- Department of Surgery, NUTRIM School for Nutrition, Toxicology and Metabolism, Maastricht University Medical Center, Maastricht 6200 MD, The Netherlands.
| | - Wouter H Lamers
- Department of Anatomy & Embryology, Maastricht University Medical Center, Maastricht 6200, The Netherlands.
| | - Anje Cauwels
- Department of Molecular Biomedical Research, VIB, Ghent B-9000, Belgium.
- Department of Biomedical Molecular Biology, Ghent University, Ghent B-9000, Belgium.
| | - Martijn Poeze
- Department of Surgery, NUTRIM School for Nutrition, Toxicology and Metabolism, Maastricht University Medical Center, Maastricht 6200 MD, The Netherlands.
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Ellithy HN, Yousri S, Shahin GH. Relation between glutathione S-transferase genes (GSTM1, GSTT1, and GSTP1) polymorphisms and clinical manifestations of sickle cell disease in Egyptian patients. Hematology 2015; 20:598-606. [DOI: 10.1179/1607845415y.0000000013] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Affiliation(s)
- Hend N. Ellithy
- Clinical Hematology UnitInternal Medicine Department, Faculty of Medicine, Cairo University, Egypt
| | - Sherif Yousri
- Clinical Pathology Department, Faculty of Medicine, Cairo University, Egypt
| | - Gehan H. Shahin
- Clinical Pathology Department, Faculty of Medicine, Cairo University, Egypt
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da Silva DGH, Ricci O, de Almeida EA, Bonini-Domingos CR. Potential utility of melatonin as an antioxidant therapy in the management of sickle cell anemia. J Pineal Res 2015; 58:178-88. [PMID: 25545035 DOI: 10.1111/jpi.12204] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/10/2014] [Accepted: 12/19/2014] [Indexed: 12/23/2022]
Abstract
This study aimed to assess antioxidant effects of melatonin treatment compared to N-acetylcysteine (NAC) and to their combination in a sickle cell suspension. Sickle erythrocytes were suspended in phosphate-buffered saline, pH 7.4, composing external control group. They were also suspended and incubated at 37°C either in the absence (experimental control group) or in the presence of NAC, melatonin and their combination at concentrations of 100 pm, 100 nm and 100 μm for 1 hr (treatment groups). The melatonin influences were evaluated by spectrophotometric [hemolysis degree, catalase (CAT), glutathione S-transferase (GST), glutathione peroxidase (GPx), glutathione reductase (GR), glucose-6-phosphate dehydrogenase (G6PDH), and superoxide dismutase (SOD) activities] and chromatographic methods [glutathione (GSH) and malondialdehyde (MDA) levels]. Incubation period was able to cause a rise about 64% on hemolysis degree as well as practically doubled the lipid peroxidation levels (P < 0.01). However, almost all antioxidants tested treatments neutralized this incubation effect observed in MDA levels. Among the antioxidant biomarkers evaluated, we observed a modulating effect of combined treatment on GPx and SOD activities (P < 0.01), which showed ~25% decrease in their activities. In addition, we found an antioxidant dose-dependent effect for melatonin on lipid peroxidation (r = -0.29; P = 0.03) and for combined antioxidant treatments also on MDA levels (r = -0.37; P = 0.01) and on SOD activity (r = -0.54; P < 0.01). Hence, these findings contribute with important insight that melatonin individually or in combination with NAC may be useful for sickle cell anemia management.
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Affiliation(s)
- Danilo Grünig Humberto da Silva
- Department of Biology, Hemoglobin and Hematologic Genetic Diseases Laboratory, UNESP - Sao Paulo State University, Sao Paulo, Brazil; Department of Chemistry and Environmental Sciences, UNESP - Sao Paulo State University, Sao Paulo, Brazil
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de Oliveira Filho RA, Silva GJ, de Farias Domingos I, Hatzlhofer BLD, da Silva Araújo A, de Lima Filho JL, Bezerra MAC, Martins DBG, de Araújo RFF. Association between the genetic polymorphisms of glutathione S-transferase (GSTM1 and GSTT1) and the clinical manifestations in sickle cell anemia. Blood Cells Mol Dis 2013; 51:76-9. [DOI: 10.1016/j.bcmd.2013.03.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2013] [Revised: 03/06/2013] [Accepted: 03/07/2013] [Indexed: 01/23/2023]
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Bueno M, Wang J, Mora AL, Gladwin MT. Nitrite signaling in pulmonary hypertension: mechanisms of bioactivation, signaling, and therapeutics. Antioxid Redox Signal 2013; 18:1797-809. [PMID: 22871207 PMCID: PMC3619206 DOI: 10.1089/ars.2012.4833] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
SIGNIFICANCE Pulmonary arterial hypertension (PAH) is a disorder characterized by increased pulmonary vascular resistance and mean pulmonary artery pressure leading to impaired function of the right ventricle, reduced cardiac output, and death. An imbalance between vasoconstrictors and vasodilators plays an important role in the pathobiology of PAH. RECENT ADVANCES Nitric oxide (NO) is a potent vasodilator in the lung, whose bioavailability and signaling pathway are impaired in PAH. It is now appreciated that the oxidative product of NO metabolism, the inorganic anion nitrite (NO(2)(-)), functions as an intravascular endocrine reservoir of NO bioactivity that can be reduced back to NO under physiological and pathological hypoxia. CRITICAL ISSUES The conversion of nitrite to NO is controlled by coupled electron and proton transfer reactions between heme- and molybdenum-containing proteins, such as hemoglobin and xanthine oxidase, and by simple protonation and disproportionation, and possibly by catalyzed disproportionation. The two major sources of nitrite (and nitrate) are the endogenous L-arginine-NO pathway, by oxidation of NO, and the diet, with conversion of nitrate from diet into nitrite by oral commensal bacteria. In the current article, we review the enzymatic formation of nitrite and the available data regarding its use as a therapy for PAH and other cardiovascular diseases. FUTURE DIRECTIONS The successful efficacy demonstrated in several animal models and safety in early clinical trials suggest that nitrite may represent a promising new therapy for PAH.
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Affiliation(s)
- Marta Bueno
- Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, PA 15213, USA
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Abstract
Although glutamine is considered the main precursor for citrulline synthesis, the current literature does not differentiate between the contribution of glutamine carbon skeleton vs. nonspecific nitrogen (i.e., ammonia) and carbon derived from glutamine oxidation. To elucidate the role of glutamine and nonspecific nitrogen in the synthesis of citrulline, l-[2-(15)N]- and l-[5-(15)N]glutamine and (15)N-ammonium acetate were infused intragastrically in mice. The amino group of glutamine labeled the three nitrogen groups of citrulline almost equally. The amido group and ammonium acetate labeled the ureido and amino groups of citrulline, but not the delta-nitrogen. D(5)-glutamine also infused in this arm of the study, which traces the carbon skeleton of glutamine, was utilized poorly, accounting for only 0.2-0.4% of the circulating citrulline. Dietary glutamine nitrogen (both N groups) incorporation was 25-fold higher than the incorporation of its carbon skeleton into citrulline. To investigate the relative contributions of the carbon skeleton and nonspecific carbon of glutamine, arginine, and proline to citrulline synthesis, U-(13)C(n) tracers of these amino acids were infused intragastrically. Dietary arginine was the main precursor for citrulline synthesis, accounting for approximately 40% of the circulating citrulline. Proline contribution was minor (3.4%), and glutamine was negligible (0.4%). However, the glutamine tracer resulted in a higher enrichment in the ureido group, indicating incorporation of nonspecific carbon from glutamine oxidation into carbamylphosphate used for citrulline synthesis. In conclusion, dietary glutamine is a poor carbon skeleton precursor for the synthesis of citrulline, although it contributes both nonspecific nitrogen and carbon to citrulline synthesis.
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Affiliation(s)
- Juan C Marini
- Children's Nutrition Research Center, Department of Pediatrics, United States Department of Agriculture/Agricultural Research Service, 1100 Bates Street, Houston, TX 77030, USA.
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