Decreased plasma concentrations of l -hydroxy-arginine as a marker of reduced NO formation in patients with combined cardiovascular risk factors


      Patients with metabolic syndrome represent a group with extensive cardiovascular risk factors for the development of atherosclerosis, which may be preceded by an impairment of endothelial function. Endothelial dysfunction is characterized by a reduced availability of bioactive nitric oxide, the principal mediator of endothelium-dependent vasodilation. In the present study we assessed NO synthesis in vivo by measuring the NO-related amino acids l -arginine and l -citrulline and in particular the stable intermediate compound N ω-hydroxy-l -arginine (l -NHA) in patients with metabolic syndrome by using high-performance liquid chromatography (HPLC) analysis. As a prerequisite to our study, we measured the amino acid concentrations in 31 healthy volunteers to investigate gender and age differences. To prove whether blood drawn from peripheral veins reflects plasma concentrations of the whole vessel system, several blood samples from different regions were obtained from patients undergoing elective left and right heart catheterization. In the latter group, no significant differences were noted among the plasma concentrations between the different sample sites. In healthy volunteers, there were no significant differences in plasma concentrations of any one specific amino acid between males and females or age groups. The main finding of the study is that the intermediate product of NO synthesis, l -NHA, is significantly reduced in the plasma samples of patients with a metabolic syndrome as compared with samples from healthy control subjects. The plasma concentrations of the NO precursor l -arginine and the end product of NO synthesis, l -citrulline, were unchanged. In conclusion, our results suggest that plasma levels of l -NHA are independent of age and gender and are not different at various locations within the vascular system. In a group of patients at high risk for the development of atherosclerosis, we found reduced plasma concentrations of l -NHA, either caused by a decreased endothelial NO synthase activity or caused by an increased breakdown of l -NHA by pathways independent of NO synthase, resulting in a reduced availability of l -NHA for NO synthesis. (J Lab Clin Med 2000;135:419-25)


      eNOS (endothelial nitric oxide), HDL (high-density lipoprotein), HPLC (high-performance liquid chromatography), iNOS (inducible nitric oxide), LDL (low-density lipoprotein), l-NHA (Nω-hydroxy-l-arginine), NO (nitric oxide), NOS (nitric oxide synthase)
      To read this article in full you will need to make a payment

      Purchase one-time access:

      Academic & Personal: 24 hour online accessCorporate R&D Professionals: 24 hour online access
      One-time access price info
      • For academic or personal research use, select 'Academic and Personal'
      • For corporate R&D use, select 'Corporate R&D Professionals'


      Subscribe to Translational Research
      Already a print subscriber? Claim online access
      Already an online subscriber? Sign in
      Institutional Access: Sign in to ScienceDirect


        • Reaven GM
        Role of insulin resistance in human disease.
        Diabetes. 1988; 37: 1595-1607
        • Ross R
        The pathogenesis of atherosclerosis: a perspective for the 1990s.
        Nature. 1993; 362: 801-809
        • Zeiher AM
        • Drexler H
        • Wollschlager H
        • Just H
        Modulation of coronary vasomotor tone in humans. Progressive endothelial dysfunction with different early stages of coronary atherosclerosis.
        Circulation. 1991; 83: 391-401
        • Panza JA
        • Quyyumi AA
        • Brush JEJ
        • Epstein SE
        Abnormal endothelium-dependent vascular relaxation in patients with essential hypertension.
        N Engl J Med. 1990; 323: 22-27
        • Lehmann ED
        • Riley WA
        • Clarkson P
        • Gosling RG
        Non-invasive assessment of cardiovascular disease in diabetes mellitus.
        Lancet. 1997; 350: SI14-SI19
        • Williams SB
        • Cusco JA
        • Roddy MA
        • Johnstone MT
        • Creager MA
        Impaired nitric oxide-mediated vasodilation in patients with non-insulin-dependent diabetes mellitus.
        J Am Coll Cardiol. 1996; 27: 567-574
        • Michel T
        • Feron O
        Nitric oxide synthases: which, where, how and why?.
        J Clin Invest. 1998; 100: 2146-2152
        • Flavahan NA
        Atherosclerosis or lipoprotein-induced endothelial dysfunction. Potential mechanisms underlying reduction in EDRF/nitric oxide activity.
        Circulation. 1992; 85: 1927-1938
        • Wever RM
        • Luscher TF
        • Cosentino F
        • Rabelink TJ
        Atherosclerosis and the two faces of endothelial nitric oxide synthase.
        Circulation. 1998; 97: 108-112
        • Panza JA
        • Garcia CE
        • Kilcoyne CM
        • Quyyumi AA
        • Cannon RO
        Impaired endothelium-dependent vasodilation in patients with essential hypertension. Evidence that nitric oxide abnormality is not localized to a single signal transduction pathway.
        Circulation. 1995; 91: 1732-1738
        • Suzuki H
        • Ikenaga H
        • Hishikawa K
        • Nakaki T
        • Kato R
        • Saruta T
        Increases of NO2/NO3-excretion in the urine as an indicator of the release of endothelium-derived relaxing factor during elevation of blood pressure.
        Clin Sci. 1992; 82: 631-634
        • Takahashi H
        • Nakanishi T
        • Nishimura M
        • Tanaka H
        • Yoshimura M
        Measurement of serum levels of nitrate ions in men and women. Implications of endothelium-derived relaxing factor in blood pressure regulation and atherosclerosis.
        J Cardiovasc Pharmacol. 1992; 20: 214
        • Boger RH
        • Bode BS
        • Gerecke U
        • Frolich JC
        Long-term administration of L -arginine, L -NAME and the exogenous NO donor molsidomine modulates urinary nitrate and cGMP excretion in rats.
        Cardiovasc Res. 1994; 28: 494
        • Boger RH
        • Bode BS
        • Mugge A
        • Kienke S
        • Brandes R
        • Dwenger A
        • et al.
        Supplementation of hypercholesterolaemic rabbits with L -arginine reduces the vascular release of superoxide anions and restores NO production.
        Atherosclerosis. 1995; 117: 273-284
        • Boger RH
        • Bode BS
        • Brandes RP
        • Phivthong NL
        • Bohme M
        • Nafe R
        • et al.
        Dietary L -arginine reduces the progression of atherosclerosis in cholesterol-fed rabbits: comparison with lovastatin.
        Circulation. 1997; 96: 1282-1290
        • Mugge A
        • Kurucay S
        • Boger RH
        • Bode BS
        • Schäfers HJ
        • Lichtlen PR
        Urinary nitrate excretion is increased in cardiac transplanted patients with acute graft rejection.
        Clin Transplant. 1996; 10: 298-305
        • Stuehr DJ
        • Kwon NS
        • Nathan CF
        • Griffith OW
        • Feldman PL
        • Wiseman J.
        N omega-hydroxy-L -arginine is an intermediate in the biosynthesis of nitric oxide from L -arginine.
        J Biol Chem. 1991; 266: 6259-6263
        • Wigand R
        • Meyer J
        • Busse R
        • Hecker M.
        Increased serum NG-hydroxy-L -arginine in patients with rheumatoid arthritis and systemic lupus erythematosus as an index of an increased nitric oxide synthase activity.
        Ann Rheum Dis. 1997; 56: 330-332
        • Fekkes D
        State-of-the-art of high-performance liquid chromatographic analysis of amino acids in physiological samples.
        J Chromatogr B. 1996; 682: 3-22
        • Hecker M
        • Mitchell JA
        • Harris HJ
        • Katsura M
        • Thiemermann C
        • Vane JR
        Endothelial cells metabolize NG-monomethyl-L -arginine to L -citrulline and subsequently to L -arginine.
        Biochem Biophys Res Commun. 1990; 167: 1037-1043
        • Hecker M
        • Schott C
        • Bucher B
        • Busse R
        • Stoclet JC
        Increase in serum NG-hydroxy-L -arginine in rats treated with bacterial lipopolysaccharide.
        Eur J Pharmacol. 1995; 275: R1-R3
        • Everett SA
        • Dennis MF
        • Patel KB
        • Stratford MR
        • Wardman P.
        Oxidative denitrification of N omega-hydroxy-L -arginine by the superoxide radical anion.
        Biochem J. 1996; 317: 17-21
        • Schott CA
        • Bogen CM
        • Vetrovsky P
        • Berton CC
        • Stoclet JC
        Exogenous NG-hydroxy-L -arginine causes nitrite production in vascular smooth muscle cells in the absence of nitric oxide synthase activity.
        FEBS Lett. 1994; 341: 203-207
        • Higman DJ
        • Strachan AM
        • Buttery L
        • Hicks RC
        • Springall DR
        • Greenhalgh RM
        • et al.
        Smoking impairs the activity of endothelial nitric oxide synthase in saphenous vein.
        Arterioscler Thromb Vasc Biol. 1996; 16: 546-552
        • Wallace GC
        • Gulati P
        • Fukuto JM
        N omega-hydroxy-L -arginine: a novel arginine analog capable of causing vasorelaxation in bovine intrapulmonary artery.
        Biochem Biophys Res Commun. 1991; 176: 528-534
        • Celermajer DS
        • Adams MR
        • Clarkson P
        • Robinson J
        • McCredie R
        • Donald A
        • et al.
        Passive smoking and impaired endothelium-dependent arterial dilatation in healthy young adults.
        N Engl J Med. 1996; 334: 150-154
        • Ruschitzka FT
        • Noll G
        • Luscher TF
        The endothelium in coronary artery disease.
        Cardiology. 1997; 88: 3-19
        • Drexler H
        • Kurz S
        • Jeserich M
        • Munzel T
        • Hornig B
        Effect of chronic angiotensin-converting enzyme inhibition on endothelial function in patients with chronic heart failure.
        Am J Cardiol. 1995; 76: 13E-18E
        • Stroes ES
        • Koomans HA
        • de Bruin TW
        • Rabelink TJ
        Vascular function in the forearm of hypercholesterolaemic patients off and on lipid-lowering medication.
        Lancet. 1995; 346: 467-471
        • Haller H
        Modulation of endothelial function: strategy for long-term cardiovascular protection.
        J Hypertens Suppl. 1996; 14: S27-S32
        • Celermajer DS.
        Endothelial dysfunction: does it matter? Is it reversible?.
        J Am Coll Cardiol. 1997; 30 (1997): 325-333