Diminished L-arginine bioavailability in hypertension

2004 ◽  
Vol 107 (4) ◽  
pp. 391-397 ◽  
Author(s):  
Monique B. MOSS ◽  
Tatiana M. C. BRUNINI ◽  
Roberto SOARES de MOURA ◽  
Lúcia E. NOVAES MALAGRIS ◽  
Norman B. ROBERTS ◽  
...  
Keyword(s):  
Amino Acid ◽  
Blood Cells ◽  
Human Platelets ◽  
Transport Systems ◽  
No Production ◽  
Hypertensive Patients ◽  
Spontaneously Hypertensive ◽  
Cationic Amino Acid ◽  
Arginine Transport ◽  
Amino Acid Profiles

L-Arginine is the precursor of NO (nitric oxide), a key endogenous mediator involved in endothelium-dependent vascular relaxation and platelet function. Although the concentration of intracellular L-arginine is well above the Km for NO synthesis, in many cells and pathological conditions the transport of L-arginine is essential for NO production (L-arginine paradox). The present study was designed to investigate the modulation of L-arginine/NO pathway in systemic arterial hypertension. Transport of L-arginine into RBCs (red blood cells) and platelets, NOS (NO synthase) activity and amino acid profiles in plasma were analysed in hypertensive patients and in an animal model of hypertension. Influx of L-arginine into RBCs was mediated by the cationic amino acid transport systems y+ and y+L, whereas, in platelets, influx was mediated only via system y+L. Chromatographic analyses revealed higher plasma levels of L-arginine in hypertensive patients (175±19 μmol/l) compared with control subjects (137±8 μmol/l). L-Arginine transport via system y+L, but not y+, was significantly reduced in RBCs from hypertensive patients (60±7 μmol·l−1·cells−1·h−1; n=16) compared with controls (90±17 μmol·l−1·cells−1·h−1; n=18). In human platelets, the Vmax for L-arginine transport via system y+L was 86±17 pmol·109 cells−1·min−1 in controls compared with 36±9 pmol·109 cells−1·min−1 in hypertensive patients (n=10; P<0.05). Basal NOS activity was decreased in platelets from hypertensive patients (0.12±0.02 pmol/108 cells; n=8) compared with controls (0.22±0.01 pmol/108 cells; n=8; P<0.05). Studies with spontaneously hypertensive rats demonstrated that transport of L-arginine via system y+L was also inhibited in RBCs. Our findings provide the first evidence that hypertension is associated with an inhibition of L-arginine transport via system y+L in both humans and animals, with reduced availability of L-arginine limiting NO synthesis in blood cells.

scholarly journals CAT2-mediated l-arginine transport and nitric oxide production in activated macrophages

1999 ◽  
Vol 340 (2) ◽  
pp. 549-553 ◽  
Author(s):  
Donald K. KAKUDA ◽  
Matthew J. SWEET ◽  
Carol L. MACLEOD ◽  
David A. HUME ◽  
Daniel MARKOVICH
Keyword(s):  
Amino Acid ◽  
Transport System ◽  
Transport Systems ◽  
No Production ◽  
Activated Macrophages ◽  
Amino Acid Transport System ◽  
Cationic Amino Acid ◽  
Arginine Transport ◽  
Arginine Uptake ◽  
Expression Studies

Activated macrophages require L-arginine uptake to sustain NO synthesis. Several transport systems could mediate this L-arginine influx. Using competition analysis and gene-expression studies, amino acid transport system y+ was identified as the major carrier responsible for this activity. To identify which of the four known y+ transport-system genes is involved in macrophage-induced L-arginine uptake, we used a hybrid-depletion study in Xenopus oocytes. Cationic amino acid transporter (CAT) 2 antisense oligodeoxyribonucleotides abolished the activated-macrophage-mRNA-induced L-arginine transport. Together with expression studies documenting that CAT2 mRNA and protein levels are elevated with increased L-arginine uptake, our data demonstrate that CAT2 mediates the L-arginine transport that is required for the raised NO production in activated J774 macrophages.

scholarly journals Development and polarization of cationic amino acid transporters and regulators in the human placenta

2000 ◽  
Vol 278 (6) ◽  
pp. C1162-C1171 ◽  
Author(s):  
Paul T.-Y. Ayuk ◽  
Colin P. Sibley ◽  
Paul Donnai ◽  
Stephen D'Souza ◽  
Jocelyn D. Glazier
Keyword(s):  
Amino Acid ◽  
Membrane Vesicles ◽  
First Trimester ◽  
Transport Systems ◽  
Amino Acid Transporters ◽  
Rt Pcr ◽  
Plasma Membrane Vesicles ◽  
Michaelis Constant ◽  
Cationic Amino Acid ◽  
Arginine Transport

We have investigatedl-arginine transport systems in the human placental syncytiotrophoblast across gestation using purified microvillous (MVM) and basal (BM) plasma membrane vesicles. In MVM from first-trimester and term placentas, l-arginine transport was by systems y+ and y+L. In BM (term placentas), however, there was evidence for system y+L only. The Michaelis constant of system y+L was significantly lower ( P< 0.05) in first-trimester compared with term MVM and lower in term MVM compared with BM ( P < 0.05). There was no functional evidence for system b0+ in term MVM or BM. Cationic amino acid transporter (CAT) 1, CAT 4, and 4F2hc were detected using RT-PCR in placentas throughout gestation. rBAT was not detected in term placentas. An ∼85-kDa and an ∼135-kDa protein was detected by Western blotting in MVM under reducing and nonreducing conditions, respectively, consistent with the 4F2hc monomer and the 4F2hc-light chain dimer, and their expression was significantly higher ( P< 0.05) in term compared with first-trimester MVM. These proteins were not detected in BM despite functional evidence for system y+L. These data suggest different roles for 4F2hc in the development and polarization of cationic amino acid transporters in the syncytiotrophoblast.

scholarly journals Arginine Homeostasis in J774.1 Macrophages in the Context of Mycobacterium bovis BCG Infection

2006 ◽  
Vol 188 (13) ◽  
pp. 4830-4840 ◽  
Author(s):  
Meliza T. Talaue ◽  
Vishwanath Venketaraman ◽  
Manzour Hernando Hazbón ◽  
Marcy Peteroy-Kelly ◽  
Anjali Seth ◽  
...  
Keyword(s):  
Amino Acid ◽  
Mycobacterium Bovis ◽  
Amino Acid Transport ◽  
Host Cells ◽  
Transport Systems ◽  
Acid Transport ◽  
Intracellular Growth ◽  
Cationic Amino Acid ◽  
Arginine Transport ◽  
Arginine Uptake

ABSTRACT The competition for l-arginine between the inducible nitric oxide synthase and arginase contributes to the outcome of several parasitic and bacterial infections. The acquisition of l-arginine, however, is important not only for the host cells but also for the intracellular pathogen. In this study we observe that strain AS-1, the Mycobacterium bovis BCG strain lacking the Rv0522 gene, which encodes an arginine permease, perturbs l-arginine metabolism in J774.1 murine macrophages. Infection with AS-1, but not with wild-type BCG, induced l-arginine uptake in J774.1 cells. This increase in l-arginine uptake was independent of activation with gamma interferon plus lipopolysaccharide and correlated with increased expression of the MCAT1 and MCAT2 cationic amino acid transport genes. AS-1 infection also enhanced arginase activity in resting J774.1 cells. Survival studies revealed that AS-1 survived better than BCG within resting J774.1 cells. Intracellular growth of AS-1 was further enhanced by inhibiting arginase and ornithine decarboxylase activities in J774.1 cells using l-norvaline and difluoromethylornithine treatment, respectively. These results suggest that the arginine-related activities of J774.1 macrophages are affected by the arginine transport capacity of the infecting BCG strain. The loss of Rv0522 gene-encoded arginine transport may have induced other cationic amino acid transport systems during intracellular growth of AS-1, allowing better survival within resting macrophages.

scholarly journals Increased l-arginine uptake and inducible nitric oxide synthase activity in aortas of rats with heart failure

2001 ◽  
Vol 280 (2) ◽  
pp. H859-H867 ◽  
Author(s):  
Peter B. Stathopulos ◽  
Xiangru Lu ◽  
Ji Shen ◽  
Jeremy A. Scott ◽  
James R. Hammond ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Heart Failure ◽  
Amino Acid ◽  
Nitric Oxide Synthase ◽  
No Production ◽  
Cationic Amino Acid ◽  
Arginine Transport ◽  
Arginine Uptake ◽  
Oxide Synthase

l-Arginine crosses the cell membrane primarily through the system y+ transporter. The aim of this study was to investigate the role of l-arginine transport in nitric oxide (NO) production in aortas of rats with heart failure induced by myocardial infarction. Tumor necrosis factor-α levels in aortas of rats with heart failure were six times higher than in sham rats ( P < 0.01). l-Arginine uptake was increased in aortas of rats with heart failure compared with sham rats ( P < 0.01). Cationic amino acid transporter-2B and inducible (i) nitric oxide synthase (NOS) expression were increased in aortas of rats with heart failure compared with sham rats ( P < 0.05). Aortic strips from rats with heart failure treated with l-arginine but not d-arginine increased NO production ( P < 0.05). The effect ofl-arginine on NO production was blocked byl-lysine, a basic amino acid that shares the same system y+ transporter withl-arginine, and by the NOS inhibitor N G-nitro-l-arginine methyl ester (l-NAME). Treatment with l-lysine andl-NAME in vivo decreased plasma nitrate and nitrite levels in rats with heart failure ( P < 0.05). Our data demonstrate that NO production is dependent on iNOS activity andl-arginine uptake and suggest that l-arginine transport plays an important role in enhanced NO production in heart failure.

scholarly journals l-Arginine and Cationic Amino Acid Transporter 2B Regulate Growth and Survival of Leishmania amazonensis Amastigotes in Macrophages

2007 ◽  
Vol 75 (6) ◽  
pp. 2802-2810 ◽  
Author(s):  
Nanchaya Wanasen ◽  
Carol L. MacLeod ◽  
Lesley G. Ellies ◽  
Lynn Soong
Keyword(s):  
Amino Acid ◽  
Amino Acid Transporter ◽  
Parasite Growth ◽  
Leishmania Amazonensis ◽  
Growth Enhancement ◽  
Cationic Amino Acid Transporter ◽  
Cationic Amino Acid ◽  
Arginine Transport ◽  
Ifn Γ ◽  
Acid Transporter

ABSTRACT Leishmania spp. are obligate intracellular parasites, requiring a suitable microenvironment for their growth within host cells. We previously reported that the growth of Leishmania amazonensis amastigotes in murine macrophages (Mφs) was enhanced in the presence of gamma interferon (IFN-γ), a Th1 cytokine normally associated with classical Mφ activation and killing of intracellular pathogens. In this study, we provided several lines of evidence suggesting that IFN-γ-mediated parasite growth enhancement was associated with l-arginine transport via mouse cationic amino acid transporter 2B (mCAT-2B). (i) mRNA expression of Slc7A2, the gene encoding for mCAT-2B, as well as l-arginine transport was increased in IFN-γ-treated Mφs. (ii) Supplementation of l-arginine in Mφ cultures increased parasite growth. (iii) Parasite growth enhancement in wild-type Mφs was inhibited in the presence of nonmetabolized l-arginine analogues. (iv) IFN-γ-mediated parasite growth was absent in Mφs derived from mCAT-2B-deficient mice. Although we detected a clear upregulation of mCAT-2B and l-arginine transport, no measurable iNOS or arginase activities were observed in IFN-γ-treated, infected Mφs. Together, these data suggest an involvement of a novel l-arginine usage independent of iNOS and arginase activities during IFN-γ-mediated parasite growth enhancement. A possible role of mCAT-2B in supplying l-arginine directly to the parasites for their proliferation is discussed.

Multiple pathways for cationic amino acid transport in rat thyroid epithelial cell line PC Cl3

2005 ◽  
Vol 288 (2) ◽  
pp. C290-C303 ◽  
Author(s):  
Tiziano Verri ◽  
Cinzia Dimitri ◽  
Sonia Treglia ◽  
Fabio Storelli ◽  
Stefania De Micheli ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Cell Line ◽  
Amino Acid Transport ◽  
Transport Systems ◽  
Residual Fraction ◽  
Acid Transport ◽  
Thyroid Cells ◽  
Cationic Amino Acid ◽  
Rat Thyroid

Information regarding cationic amino acid transport systems in thyroid is limited to Northern blot detection of y+LAT1 mRNA in the mouse. This study investigated cationic amino acid transport in PC cell line clone 3 (PC Cl3 cells), a thyroid follicular cell line derived from a normal Fisher rat retaining many features of normal differentiated follicular thyroid cells. We provide evidence that in PC Cl3 cells plasmalemmal transport of cationic amino acids is Na+ independent and occurs, besides diffusion, with the contribution of high-affinity, carrier-mediated processes. Carrier-mediated transport is via y+, y+L, and b0,+ systems, as assessed by l-arginine uptake and kinetics, inhibition of l-arginine transport by N-ethylmaleimide and neutral amino acids, and l-cystine transport studies. y+L and y+ systems account for the highest transport rate (with y+L > y+) and b0,+ for a residual fraction of the transport. Uptake data correlate to expression of the genes encoding for CAT-1, CAT-2B, 4F2hc, y+LAT1, y+LAT2, rBAT, and b0,+AT, an expression profile that is also shown by the rat thyroid gland. In PC Cl3 cells cationic amino acid uptake is under TSH and/or cAMP control (with transport increasing with increasing TSH concentration), and upregulation of CAT-1, CAT-2B, 4F2hc/y+LAT1, and rBAT/b0,+AT occurs at the mRNA level under TSH stimulation. Our results provide the first description of an expression pattern of cationic amino acid transport systems in thyroid cells. Furthermore, we provide evidence that extracellular l-arginine is a crucial requirement for normal PC Cl3 cell growth and that long-term l-arginine deprivation negatively influences CAT-2B expression, as it correlates to reduction of CAT-2B mRNA levels.

scholarly journals Nitric oxide can acutely modulate its biosynthesis through a negative feedback mechanism on l-arginine transport in cardiac myocytes

2010 ◽  
Vol 299 (2) ◽  
pp. C230-C239 ◽  
Author(s):  
Jiaguo Zhou ◽  
David D. Kim ◽  
R. Daniel Peluffo
Keyword(s):  
Nitric Oxide ◽  
Amino Acid ◽  
Cardiac Myocytes ◽  
Amino Acid Transporters ◽  
No Production ◽  
Cardiac Muscle Cells ◽  
No Donor ◽  
Rat Cardiomyocytes ◽  
Cationic Amino Acid ◽  
Intervention Point

Nitric oxide (NO) plays a central role as a cellular signaling molecule in health and disease. In the heart, NO decreases the rate of spontaneous beating and the velocity and extent of shortening and accelerates the velocity of relengthening. Since the cationic amino acid l-arginine (l-Arg) is the substrate for NO production by NO synthases (NOS), we tested whether the transporters that mediate l-Arg import in cardiac muscle cells represent an intervention point in the regulation of NO synthesis. Electrical currents activated by l-Arg with low apparent affinity in whole cell voltage-clamped rat cardiomyocytes were found to be rapidly and reversibly inhibited by NO donors. Radiotracer uptake studies performed on cardiac sarcolemmal vesicles revealed the presence of high-affinity/low-capacity and low-affinity/high-capacity components of cationic amino acid transport that were inhibited by the NO donor S-nitroso- N-acetyl-dl-penicillamine. NO inhibited uptake in a noncompetitive manner with Ki values of 275 and 827 nM for the high- and low-affinity component, respectively. Fluorescence spectroscopy experiments showed that millimolar concentrations of l-Arg initially promoted and then inhibited the release of endogenous NO in cardiomyocytes. Likewise, l-Arg currents measured in cardiac myocytes voltage clamped in the presence of 460 nM free intracellular Ca2+, a condition in which a Ca-CaM complex should activate endogenous NO production, showed fast activation followed by inhibition of l-Arg transport. The NOS inhibitor N-nitro-l-arginine methyl ester, but not blockers of downstream reactions, specifically removed this inhibitory component. These results demonstrate that NO acutely regulates its own biosynthesis by modulating the availability of l-Arg via cationic amino acid transporters.

Increased l-arginine Transport in Human Erythrocytes in Chronic Heart Failure

1998 ◽  
Vol 94 (1) ◽  
pp. 43-48 ◽  
Author(s):  
H. Hanssen ◽  
T. M. C. Brunini ◽  
M. Conway ◽  
A. P. Banning ◽  
N. B. Roberts ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Heart Failure ◽  
Chronic Heart Failure ◽  
Human Erythrocytes ◽  
Transport Systems ◽  
Acid Transport ◽  
Cationic Amino Acid ◽  
Arginine Transport ◽  
Healthy Donors ◽  
Patients With Heart Failure

1. Transport of l-arginine was investigated under zero-trans conditions in human erythrocytes from healthy donors and patients with heart failure. 2. Saturable influx of l-arginine was mediated by the classical cationic amino acid transport systems y+ and y+L. 3. The Vmax for l-arginine transport via system y+ increased from 292 to 490 μmol h−-1 l−-1 of cells in heart failure. 4. With system y+ inhibited by N-ethylmaleimide (0.2 mmol/l), the Vmax for the transport of l-arginine via system y+L was unaffected in erythrocytes from patients with heart failure. 5. The inhibition of l-arginine and l-leucine influx by NG-monomethyl-l-arginine was similar in erythrocytes from control and heart failure patients. 6. Plasma l-arginine levels were reduced in patients with heart failure (59 μmol/l) compared with controls (125 μmol/l). Plasma from patients with heart failure also contained the endogenous l-arginine analogue NG-monomethyl-l-arginine, which was undetectable in plasma from controls. 7. Intracellular concentrations of l-arginine and NG-monomethyl-l-arginine were significantly elevated in erythrocytes from patients with heart failure compared with controls, consistent with an increased transport capacity for l-arginine and NG-monomethyl-l-arginine. 8. The present study provides the first evidence that system y+ mediates the increased transport of l-arginine in human erythrocytes from patients with chronic heart failure. These findings are similar to our previous results obtained in patients with chronic renal failure. Since both pathologies seem to present with an increased synthesis of nitric oxide, studies of l-arginine transport in erythrocytes may provide a valuable paradigm to study abnormalities of the l-arginine-nitric oxide signalling pathway.

Characterization of l-arginine transport in adrenal cells: effect of ACTH

2006 ◽  
Vol 291 (2) ◽  
pp. E291-E297 ◽  
Author(s):  
Esteban M. Repetto ◽  
Vanesa Pannunzio ◽  
Francisco Astort ◽  
Camila Martinez Calejman ◽  
Marcos Besio Moreno ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Amino Acid ◽  
Transport System ◽  
Zona Fasciculata ◽  
Acid Uptake ◽  
Uptake System ◽  
Amino Acid Transport System ◽  
Cationic Amino Acid ◽  
Arginine Transport

Nitric oxide synthesis depends on the availability of its precursor l-arginine, which could be regulated by the presence of a specific uptake system. In the present report, the characterization of the l-arginine transport system in mouse adrenal Y1 cells was performed. l-arginine transport was mediated by the cationic/neutral amino acid transport system y+L and the cationic amino acid transporter (CAT) y+ in Y1 cells. These Na+-independent transporters were identified by their selectivity for neutral amino acids in both the presence and absence of Na+ and by the effect of N-ethylmaleimide. Transport data correlated to expression of genes encoding for CAT-1, CAT-2, CD-98, and y+LAT-2. A similar expression profile was detected in rat adrenal zona fasciculata. In addition, cationic amino acid uptake in Y1 cells was upregulated by ACTH and/or cAMP with a concomitant increase in nitric oxide (NO) production.

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