Review
Methods of quantitative analysis of the nitric oxide metabolites nitrite and nitrate in human biological fluids

References

• Furchgott RF, Zawadzki JV. The obligatory role of endothelial cells in the relaxation of arterial smooth muscle by acetylcholine. Nature 1980;288:373–376.
   PubMed Web of Science ®Google Scholar
• Palmer RMJ, Ferrige AG, Moncada S. Nitric oxide release accounts for the biological activity of endothelium-derived relaxing factor. Nature 1987;327:524–526.
   Google Scholar
• Ignarro LJ, Buga GM, Wood KS, Byrns RE, Chaudhuri G. Endothelium-derived relaxing factor produced and released from artery and vein is nitric oxide. Proc Natl Acad Sci USA 1987;84:9265–9269.
   Google Scholar
• Hibbs JB, Jr., Taintor RR, Vavrin Z. Macrophage cytotoxicity: Role for L-arginine deiminase and imino nitrogen oxidation to nitrite. Science 1987;235:473–476.
   PubMed Web of Science ®Google Scholar
• Iyengar R, Stuehr DJ, Marletta MA. Macrophage synthesis of nitrite, nitrate, and N-nitrosamines: Precursors and role of the respiratory burst. Proc Natl Acad Sci USA 1987;84:6369–6373.
   PubMed Web of Science ®Google Scholar
• Palmer RMJ, Ashton DS, Moncada S. Vascular endothelial cells synthesize nitric oxide from L-arginine. Nature 1988;333:664–666.
   Google Scholar
• Palmer RMJ, Rees DD, Ashton DS, Moncada S. L-Arginine is the physiological precursor for the formation of nitric oxide in endothelium-dependent relaxation. Biochem Biophys Res Commun 1988;153:1251–1256.
   PubMed Web of Science ®Google Scholar
• Schmidt HHHW, Nau H, Wittfoht W, Gerlach J, Prescher KE, Klein MM, Niroomand F, Böhme E. Arginine is a physiological precursor of endothelium-derived nitric oxide. Eur J Pharmacol 1988;154:213–216.
   Google Scholar
• Marletta MA, Yoon PS, Iyengar R, Leaf CD, Wishnok JS. Macrophage oxidation of L-arginine to nitrite and nitrate: Nitric oxide is an intermediate. Biochemistry 1989;27:8706–8711.
   Google Scholar
• Leaf CD, Wishnok JS, Tannenbaum SR. L-arginine is a precursor for nitrate biosynthesis in humans. Biochem Biophys Res Commun 1989;163:1032–1037.
   PubMed Web of Science ®Google Scholar
• Leaf CD, Wishnok JS, Hurley JP, Rosenblad WD, Fox JG, Tannenbaum SR. Nitrate biosynthesis in rats, ferrets and humans. Precursor studies with L-arginine. Carcinogenesis 1990;11:855–858.
   PubMed Web of Science ®Google Scholar
• Hibbs Jr., JB, Westenfelder C, Taintor R, Vavrin Z, Kablitz C, Baranowski RL, Ward JH, Menlove RL, McMurry MP, Kushner JP, Samlowski WE. Evidence for cytokine-inducible nitric oxide synthesis from L-arginine in patients receiving interleukin-2 therapy. J Chin Investig 1992;89: 867–877.
   Google Scholar
• Forte P, Copland M, Smith LM, Milne E, Sutherland J, Benjamin N. Basal nitric oxide synthesis in essential hypertension. Lancet 1997;349:837–842.
   PubMed Web of Science ®Google Scholar
• Katz SD, Khan T, Zeballos GA, Mathew L, Potharlanka P, Knecht M, Whelan J. Decreased activity of the L-arginine-nitric oxide metabolic pathway in patients with congestive haert failure. Circulation 1999;99:2113–2117.
   Google Scholar
• Marletta MA. Nitric oxide synthase structure and mechan-ism. J Biol Chem 1993;268:12231–12234.
   PubMed Web of Science ®Google Scholar
• Förstermann U, Gloss El, Pollock JS, Nakane M, Schwarz P, Gath I, Kleinert H. Nitric oxide synthase isozymes: Characterization, purification, molecular cloning, and func-tions. Hypertension 1994;23:1121–1131.
   Google Scholar
• Andrew PJ, Mayer B. Enzymatic function of nitric oxide synthases. Cardiovasc Res 1999;43:521–531.
   PubMed Web of Science ®Google Scholar
• Kwon NS, Nathan CF, Gilker C, Griffith OW, Matthews DE, Stuehr DJ. L-Citrulline production from L-arginine by macrophage nitric oxide synthase. The ureido oxygen derives from dioxygen. J Biol Chem 1990;265:13442–13445.
   PubMed Web of Science ®Google Scholar
• Stuehr DJ, Kwon NS, Nathan CF, Griffith OW, Feldman PL, Wiseman J. N'-Hydroxy-L-arginine is an intermediate in the biosynthesis of nitric oxide from L-arginine. J Biol Chem 1991;266:6259–6263.
   PubMed Web of Science ®Google Scholar
• Leone AM, Palmer RMJ, Knowles RG, Francis PL, Ashton D, Moncada S. Constitutive and inducible nitric oxide synthases incorporate molecular oxygen into both nitric oxide and citrulline. J Biol Chem 1991;266:23790–23795.
   PubMed Web of Science ®Google Scholar
• Vallance P, Leone A, Calver A, Collierr J, Moncada S. Accumulation of an endogenous inhibitor of nitric oxide synthesis in chronic renal failure. Lancet 1992;339:572–575.
   Google Scholar
• Leiper J, Vallance P. Biological significance of endogenous methylarginines that inhibit nitric oxide synthases. Cardio-vasc Res 2003;43:542–548.
   Google Scholar
• Pou S, Pou WS, Bredt DS, Snyder SH, Rosen GM. Generation of superoxide by purified brain nitric oxide synthase. J Biol Chem 1992;267:24173–24176.
   Google Scholar
• Stamler JS, Singel DJ, Loscalzo J. Biochemistry of nitric oxide and its redox-activated forms. Science 1992;258:1898–1902.
   Google Scholar
• Feldman PL, Griffith OW, Stuehr DJ. The surprising life of nitric oxide. Chem Eng News 1993;71:26–38.
   Google Scholar
• Pogrebnaya VL, Usov AP, Baranov AV, Nesterenko Al, Bez'yazychnyi PI. Oxidation of nitric oxide by oxygen in the liquid phase. J Appl Chem USSR 1975;48:1004–1007.
   Google Scholar
• Ford PC, Wink DA, Standbury DM. Autoxidation kinetics of aqueous nitric oxide. FEBS Lett 1993;326:1–3.
   Google Scholar
• Tsikas D, Sandmann J, Frolich JC. 2002., Measurement of S-nitrosoalbumin by gas chromatography—mass spectro-metry. III. Quantitative determination in human plasma after specific conversion of the S-nitroso group to nitrite by cysteine and Cu2+ via intermediate formation of S-nitrosocysteine and nitric oxide.
   Google Scholar
• Myers PR, Minor RL, Jr., Guerra R, Jr., Bates JN, Harrison DG. Vasorelaxant properties of the endothelium-derived relaxing factor more closely resemble S-nitrosocysteine than nitric oxide. Nature 1990;345:161–163.
   Google Scholar
• Stamler JS, Jaraki 0, Osborne J, Simon DI, Keaney J, Vita J, Singel D, Valeri CR, Loscalzo J. Nitric oxide circulates in mammalian plasma primarily as an S-nitroso adduct of serum albumin. Proc Natl Acad Sci USA 1992;89:7674–7677.
   Google Scholar
• Tsikas D, Sandmann J, Luef3en P, Savva A, Rossa S, Stichtenoth DO, Frölich JC. S-Transnitrosylation of albumin in human plasma and blood in vitro and in vivo in the rat. Biochim Biophys Acta 2001;1546:422–434.
   Google Scholar
• Xia Y, Zweier JL. Superoxide and peroxynitrite generation from inducible nitric oxide synthase in macrophages. Proc Natl Acad Sci USA 1997;94:6954–6958.
   PubMed Web of Science ®Google Scholar
• Vásquez-Vivar J, Kalyanaraman B, Martasek P, Hogg N, Masters BSS, Karoui H, Tordo H, Pritchard KA. Superoxide generation by endothelial nitric oxide synthase: The influence of cofactors. Proc Natl Acad Sci USA 1998;95:9225–9229.
   Google Scholar
• Huie RE, Padmaja S. The reaction of NO with superoxide. Free Radic Res Commun 1993;18:195–199.
   PubMed Web of Science ®Google Scholar
• Halliwell B, Gutteridge JMC. Free radicals in biology and medicine. Oxford: Oxford University Press; 1999.
   Google Scholar
• Hobbs AJ, Fukuto JM, Ignarro U. Formation of free nitric oxide from L-arginine by nitric oxide synthase: Direct enhancement of generation by superoxide dismutase. Proc Natl Acad Sci USA 1994;91:10992–10996.
   Google Scholar
• Radi R, Peluffo G, Alvarez MN, Naviliat M, Cayota A. Unravelling peroxynitrite formation in biological systems. Free Radic Biol Med 2001;30:463–488.
   PubMed Web of Science ®Google Scholar
• Pfeiffer S, Gorren ACF, Schmidt K, Werner ER, Hansert B, Bole DS, Mayer B. Metabolic fate of peroxynitrite in aqueous solution: Reaction with nitric oxide and pH-dependent decomposition to nitrite and oxygen in a 2:1 stoichiometry. J Biol Chem 1997;272: 3465–3470.
   Google Scholar
• Kissner R, Koppenol W. Product distribution of peroxynitrite decay as a function of pH, temperature, and concentration. J Am Chem Soc 2002;124:234–239.
   PubMedGoogle Scholar
• Herold S, Exner M, Nauser T. Kinetic and mechanistic studies of the NO-mediated oxidation of oxymyoglobin and oxyhemoglobin. Biochemistry 2001;40:3385–3395.
   Google Scholar
• Wennmalm A, Benthin G, Petersson AS. Dependence of the metabolism of nitric oxide (NO) in healthy human whole blood on the oxygenation of its red cell haemoglobin. Br J Pharmacol 1992;106:507–508.
   Google Scholar
• Wennmalm A, Benthin G, Edlund A, Jungsten L, Kieler-Jensen N, Lundin S, Westfelt UN, Petersson AS, Waagstein F. Metabolism and excretion of nitric oxide in humans: An experimental and clinical study. Circ Res 1993;73:1121–1127.
   Google Scholar
• Tsikas D, Stichtenoth DO, Boger RH, Bode-Boger SM, Folich JC. Synthesis of nitric oxide releasing, vasodilating and platelet aggregation inhibiting S115N]nitroso compounds. J Lab Comp Radiopharmac 1994;34: 1055–1062.
   Google Scholar
• Tsikas D, Boger RH, Bode-Boger SM, Gutzki FM, Frölich JC. Quantification of nitrite and nitrate in human urine and plasma as pentafluorobenzyl derivatives by gas chromato-graphy-mass spectrometry using their "N-labelled analogs. J Chromatogr B 1994;661:185–191.
   Google Scholar
• Joshi NS, Ferguson TB, Jr, Han TH, Hyduke DR, Liao JC, Rassaf T, Bryan N, Feelisch M, Lancaster JR, Jr. Nitric oxide is consumed, rather than conserved, by reaction with oxyhemoglobin under physiological conditions. Proc Natl Acad Sci USA 2002;99:10341–10346.
   Google Scholar
• Schechter AN, Gladwin MT. Hemoglobin and the paracrine and endocrine functions of nitric oxide. N Engl J Med 2003;348:1483–1485.
   PubMed Web of Science ®Google Scholar
• Rhodes P, Leone AM, Francis PL, Struthers AD, Moncada S. The L-arginine:nitric oxide pathway is the major source of plasma nitrite in fasted humans. Biochem Biophys Res Commun 1995;209:590–596.
   Google Scholar
• Tsikas D. Measurement of nitric oxide synthase activity in vivo and in vitro by gas chromatography-mass spectro-metry. Meth Mol Biol 2004;279:81–104.
   PubMedGoogle Scholar
• Vallance P, Patton S, Bhagat K, MacAllister R, Radomski M, Moncada S, Malinski T. Direct measurement of nitric oxide in human beings. Lancet 1995;345:153–154.
   Google Scholar
• Kelm M, Schrader J. Control of coronary vascular tone by nitric oxide. Circ Res 1990;66:1561–1575.
   PubMed Web of Science ®Google Scholar
• Gustafsson LE, Leone AM, Persson MG, Wiklund NP, Moncada S. Endogenous nitric oxide is present in the exhaled air of rabbits, guinea pigs and humans. Biochem Biophys Res Commun 1991;181:852–857.
   Google Scholar
• Bode-Boger SM, Boger RH, Löffier M, Tsikas D, Brabant G, Frölich JC. L-arginine stimulates NO-dependent vasodilation in healthy humans: Effect of somatostatin pretreatment. J Investig Med 1999;47:43–50.
   Google Scholar
• Lauer T, Preik M, Rassaf T, Strauer BE, Deussen A, Feelisch M, Kelm M. Plasma nitrite rather than nitrate reflects regional endothelial nitric oxide synthase activity but lacks intrinsic vasodilator action. Proc Natl Acad Sci USA 2001;98:12814–12819.
   Google Scholar
• Kleinbongard P, Dejam A, Lauer T, Rassaf T, Schindler A, Picker 0, Scheeren T, Godecke A, Schrader J, Schulz R, Heusch G, Schaub GA, Bryan NS, Feelisch M, Kelm M. Plasma nitrite reflects constitutive nitric oxide synthase activity in mammals. Free Radic Biol Med 2003; 35:790–796.
   Google Scholar
• Kanno K, Hirata Y, Emori T, Ohta K, Egush S, Imai T, Marumo F. L-arginine infusion induces hypotension and diuresis/natriuresis with concomitant increased urinary excretion of nitrite/nitrate and cyclic GMP in humans. Chin Exp Pharmacol Physiol 1992;19:619–625.
   Google Scholar
• Bode-Boger SM, Boger RH, Creutzig A, Tsikas D, Gutzki FM, Alexander K, Frölich JC. L-arginine infusion decreases peripheral resistance and inhibits platelet aggregation in healthy subjects. Chin Sci 1994;87:303–310.
   Google Scholar
• Borgonio A, Witte K, Stahrenberg R, Lemmer B. Influence of circadian time, ageing, and hypertension on the urinary excretion of nitric oxide metabolites in rats. Mech Ageing Dev 1999;111:23–37.
   PubMed Web of Science ®Google Scholar
• Bode-Boger SM, Boger RH, Kielstein JT, Löffler M, Schaffer J, Frölich JC. Role of endogenous nitric oxide in circadian blood pressure regulation in healthy humans and in patients with hypertension or atherosclerosis. J Investig Med 2000; 48:125–132.
   Google Scholar
• Elherik K, Khan F, McLaren M, Kennedy G, Belch JJF. Circadian variation in vascular tone and endothelial cell function in normal males. Chin Sci 2002;102:547–552.
   Google Scholar
• Keimer R, Stutzer FK, Tsikas D, Troost R, Gutzki FM, Frölich JC. Lack of oxidative stress during sustained theapy with isosorbide dinitrate and pentaerythrityl tetranitrate in healthy humans: A randomized, double blind crossover study. J Cardiovasc Pharmacol 2003;41:284–292.
   Google Scholar
• Tsikas D. Simultaneous derivatization and quantification of the nitric oxide netabolites nitrite and nitrate in biological fluids by gas chromatography-mass spectrometry. Anal Chem 2000;72:4064–4072.
   PubMed Web of Science ®Google Scholar
• Ellis G, Adatia I, Yazdanpanah M, Makela SK. Nitrite and nitrate analyses: A clinical biochemistry perspective. Chin Biochem 1998;31:195–220.
   Google Scholar
• Tsikas D. Analysis of the L-arginine/nitric oxide pathway: The unique role of mass spectrometry. Curr Pharmaceut Anal 2005;1:15–30.
   Google Scholar
• Tsikas D, Caidahl K. Recent methodological advances in the mass spectrometric analysis of free and protein-associated 3-nitrotyrosine in human plasma. J Chromatogr B 2005; 814:1–9.
   PubMedGoogle Scholar
• Tsikas D, Gutzki FM, Rossa S, Bauer H, Neumann C, Dockendorff K, Sandmann J, Frolich JC. Measurement of nitrite and nitrate in biological fluids by gas chromato-graphy-mass spectrometry and by the Griess assay: Problems with the Griess assay-Solutions by gas chromatography-mass spectrometry. Anal Biochem 1997;244:208–220.
   PubMed Web of Science ®Google Scholar
• Misko TP, Schilling RJ, Salvemini D, Moore WM, Currie MG. A fluorometric assay for the measurement of nitrite in biological samples. Anal Biochem 1993;214:11–16.
   PubMed Web of Science ®Google Scholar
• Moshage H, Kok B, Huizenga JR, Jansen PLM. Nitrite and nitrate determinations in plasma: A critical evaluation. Chin Chem 1995;41:892–896.
   Google Scholar
• Marzinzig M, Nussler AK, Stadler J, Marzinzig E, Barthlen W, Nussler NC, Berger HG, Morris SM, Bruckner UB. Improved methods to measure end products of nitric oxide in biological fluids: Nitrite, nitrate, and S-nitrosothiols. Nitric Oxide 1997;1:177–189.
   PubMed Web of Science ®Google Scholar
• Tesch JW, Rehg WR, Sievers RE. Microdetermination of nitrates and nitrites in saliva, blood, water, and suspended particulates in air by gas chromatography. J Chromatogr 1976;126:743–755.
   Google Scholar
• Green LC, Wagner DA, Glokowski J, Skipper PL, Wishnok JS, Tannenbaum SR. Analysis of nitrate, nitrite and [15N]nitrate in biological fluids. Anal Biochem 1982;126:131–138.
   PubMed Web of Science ®Google Scholar
• Farell AJ, Blake DR, Palmer RMJ, Moncada S. Increased concentrations of nitrite in synovial fluid and serum samples suggest increased nitric oxide synthesis in rheumatic diseases. Ann Rheum Dis 1992;51:1219–1222.
   Google Scholar
• Leone AM, Francis PL, Rhodes P, Moncada S. A rapid and simple method for the measurement of nitrite and nitrate in plasma by high-performance capillary electrophoresis. Bio-chem Biophys Res Commun 1994;200:951–957.
   PubMed Web of Science ®Google Scholar
• Ueda T, Maekawa T, Sadamitsu D, Oshita S, Ogino K, Nakamura K. The determination ofnitrite and nitrate in human blood plasma by capillary zone electrophoresis. Electrophoresis 1995;16:1002–1004.
   PubMedGoogle Scholar
• Preik-Steinhoff H, Kelm M. Determination of nitrite in human blood by combination of a specific sample preparation with high-performance anion-exchange chromatography and electro-chemical detection. J Chromatogr B 1996;685:348–352.
   Google Scholar
• El Menyawi I, Looareesuwan S, Knapp S, Thalhammer F, Stoiser B, Burgmann H. Measurement of serum nitrite/ nitrate concenterations using high-performance liquid chro-matography. J Chromatogr 1998;706:347–351.
   Google Scholar
• Smythe GA, Matanovic G, Yi D, Duncan MW. Trifluoroacetic anhydride-catalyzed nitration of toluene as an approach to the specific analysis of nitrate by gas chromatography-mass spectrometry. Nitric Oxide 1999;3:67–74.
   Google Scholar
• Tsikas D, Gutzki FM, Sandmann J, Schwedhelm E, Frolich JC. Quantification of plasma and urinary nitrate after ist reduction to nitrite and to the pentafluorobenzyl derivative by gas chromatography-tandem mass spectrometry. J Chroma-togr B 1999;731:285–301.
   Google Scholar
• Tsikas D, Rossa S, Sandmann J, Frolich JC. High-performance liquid chromatographic analysis of nitrite and nitrate in human plasma as S-nitroso-N- acetylcysteine with ultraviolet absor-bance detection. J Chromatogr B 1999;724:199–201.
   Google Scholar
• Pinto PCAG, Lima JLFC, de Sousa Saraiva MLMF. Sequential injection analysis of nitrites and nitrates in human serum using nitrate reductase. Chin Chim Acta 2003; 337:69–76.
   Google Scholar
• Radomski JL, Palmiri C, Heran WL. Concentrations of nitrate in normal human urine and the effect of nitrate ingestion. Toxicol Appl Pharmacol 1978;45:63–68.
   Google Scholar
• Bode-Boger SM, Boger RH, Schröder EP, Frolich JC. Exercise increase systemic nitric oxide production in men. J Cardiovasc Risk 1994;1:173–178.
   Google Scholar
• Tsikas D. Mass spectrometry-validated HPLC method for urinary nitrate. Chin Chem 2004;50:1259–1261.
   Google Scholar
• Smith C CT, Stanyer L, Betteridge DJ. Evaluation of methods for the extraction of nitrite and nitrate in biological fluids employing high-performance anion-exchange liquid chromatography for their determination. J Chromatogr B 2002;779:201–209.
   Google Scholar
• Ricart-Jane D, Llobera M, Upez-Tejero MD. Anticoagulants and other preanalytical factors interfere in plasma nitrate/ nitrite quantification by the Griess method. Nitric Oxide 2002;6:178–185.
   Google Scholar
• Greenberg SS, Xie J, Spitzer H, Wang J, Lancaster J, Grisham MB, Powers DR, Giles TD. Nitro containing L-arginine analogs interfere with assays for nitrate and nitrite. Life Sci 1995;57:1949–1961.
   PubMed Web of Science ®Google Scholar
• Tsikas D, Fuchs I, Gutzki FM, Frolich JC. Measurement of nitrite and nitrate in plasma, serum and urine of humans by high-performance liquid chromatography, the Griess assay, chemiluminescence and gas chromatography-mass spectro-metry: Interferences by biogenic amines and NG-nitro-L-arginine analogs. J Chromatogr B 1998;715:441–444.
   Google Scholar
• Cox RD. Determination of nitrate and nitrite at the parts per billion level by chemiluminescence. Anal Chem 1980; 52:332–335.
   Web of Science ®Google Scholar
• Dunham AJ, Barkley RM, Sievers RE. Aqueous nitrite ion determination by selective reduction and gas phase nitric oxide chemiluminescence. Anal Chem 1995;67:220–224.
   Google Scholar
• Yang BK, Vivas EX, Reiter CD, Gladwin MT. Methodologies for the sensitive and specific measurement of S-nitrosothiols, iron-nitrosyls, and nitrite in biological samples. Free Radic Res 2003;37:1–10.
   PubMed Web of Science ®Google Scholar
• Griess P. Bemerkungen zu der Abhandlung der HH. Weselsky und Denedikt "Ueber einige Azoverbindungen". Ber Deutsch Chem Ges 1879;12:426–428.
   Google Scholar
• Damiani P, Burini G. Fluorometric determination of nitrite. Talanta 1986;33:649–652.
   PubMed Web of Science ®Google Scholar
• Noda H, Minemoto M, Noda A, Matsuyama K, Iguchi S, Kohinata T. High-performance liquid chromatographic determination of nitrite ion by use of hydralazine. Chem Pharm Bull 1980;28:2541–2542.
   Google Scholar
• Li H, Meininger CJ, Wu G. Rapid determination of nitrite by reversed-phase high-performance liquid chromatography with fluorescence detection. J Chromatogr B 2000;746:199–207.
   Google Scholar
• Davison W, Woof C. Interference studies in the batch determination of nitrate in freshwater by reduction with cadmium to nitrite. Analyst 1979;104:385–390.
   Web of Science ®Google Scholar
• Verdon CP, Burton BA, Prior RL. Sample pretreatment with nitrate reductase and glucose-6-phosphate dehydrogenase quantitatively reduces nitrate while avoiding interferences by NADP± when the Griess reaction is used to assay for nitrite. Anal Biochem 1995;224: 502–508.
   Google Scholar
• Dunphy MJ, Goble DD, Smith DJ. Nitrate analysis by capillary gas chromatography. Anal Biochem 1990;184: 381–387.
   Google Scholar
• Gutzki FM, Tsikas D, Alheid U, Frolich JC. Determination of endothelium-derived nitrite/nitrate by gas chromato-graphy/tandem mass spectrometry using (15N)NaNO2 as internal standard. Biol Mass Spectrom 1992;21:97–102.
   PubMedGoogle Scholar
• Wu HL, Chen SH, Lin SJ, Hwang WR, Funazo K, Tanaka M, Shono T. Gas chromatographic determination of inorganic anions as pentafluorobenzyl derivatives. J Chromatogr 1983;269:183–190.
   Google Scholar
• Kage S, Kudo K, Ikeda N. Simultaneous determination of nitrate and nitrite in human plasma by gas chromatography-mass spectrometry. J Anal Toxicol 2002;26:320–324.
   Google Scholar
• Giustarini D, Rossi R. Plasma S-nitrosothiols and chronic renal failure. Am J Physiol Renal Physiol 2004;287:F1294–F1295.
   Google Scholar
• Tsikas D. S-Nitrosoalbumin and other S-nitrosothiols in the blood: Is their quantity of no relevance? Circ Res 2004;94: el06.
   Google Scholar
• Duncan MW. A review of approaches to the analysis of 3-nitrotyrosine. Amino Acids 2003;25:351–361.
   PubMed Web of Science ®Google Scholar
• Tsikas D. Handling of commercially available enzyme immu- noassays for 8-iso-prostaglandin Fa, (8-iso-PGF2,„15-F2-IsoP) in clinical research and science: Considerations from the analytical and review point of view. Clin Chim Acta 2004;344:215–217.
   Google Scholar
• Schwedhelm E, Maas R, Boger RH, Brommer J, Berger J, Bartling A, Lenzen H, Tsikas D, Gutzki FM, Frolich JC. 8-iso-Prostaglandin Fa, as a risk marker in patients with coronary heart disease. Circulation 2004; 110:e49—e50.
   Google Scholar
• Becker AJ, Cckert S, Tsikas D, Noack H, Stief CG, Frolich JC, Wolf G, Jonas U. Determination of nitric oxide metabolites by means of the Griess assay and gas chromatography—mass spectrometry in the cavernous and systemic blood of healthy males and patients with erectile dysfunction during different functional conditions of the penis. Urol Res 2000;28:364–369.
   PubMedGoogle Scholar
• Heckmann M, Kreuder J, Riechers K, Tsikas D, Boedeker RH, Reiss I, Gormer L. Plasma arginine and urinary nitrate and nitrite excretion in bronchopulmonary dysplasia. Biol Neonate 2004;85:173–178.
   Google Scholar
• Shah VP, Midha KK, Dighe S, McGilveray IJ, Skelly JP, Yacobi A, layloff T, Viswanathan CT, Cook CE, McDowall RD, Pittmann KA, Spector S. Analytical methods validation: Bioavailability, bioequivalence, and pharmacokinetic studies. J Pharmaceut Sci 1992;81:309–312.
   Web of Science ®Google Scholar
• Bland JM, Altman DG. Statistical methods for assessing agreement between two methods of clinical measurement. Lancet 1986;1:307–310.
   PubMed Web of Science ®Google Scholar
• Porter AMW. Misuse of correlation and regression in three medical journals. J R Soc Med 1999;92:123–128.
   Google Scholar