Summary
The aim of the present study was to investigate the metabolism of the two NO-synthase inhibitors NG-nitro-L-arginine (L-NA) and NG-nitro-Lrarginine methylester (L-NAME) in canine blood in vitro. Blood and plasma samples were incubated with IrNAME or L-NA respectively and the drug levels were determined in blood, plasma and blood cells by means of high performance liquid chromatography.
Incubation of blood or plasma with LrNAME revealed that L-NAME is metabolized to L-NA in blood and plasma. After plasma incubation with L-NA, the L-NA levels remain stable over the whole observation period; in agreement with the data in plasma the whole amount of LNA added to blood was detectable in blood after 4 h of incubation suggesting that L-NA undergoes no further metabolism. Drug concentrations determined in blood cells after 4 h of blood incubation with L-NAME or LNA revealed that L-NAME easily enters the blood cells, whereas only a small portion of LNA is found in the blood cells 4 h after blood incubation with L-NA.
In conclusion, the present study demonstrates that L-NAME is metabolized to L-NA in canine blood and plasma in vitro. The fact that L-NAME but nearly no L-NA enters the cellular blood compartment led us to the assumption that although L-NA is an active metabolite of L-NAME, NO synthase may be differently inhibited by L-NA and L -NAME due to their different distribution characteristics.
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References
Amir S, English AM (1991) An inhibitor of nitric oxide production, NG-nitro-L-arginine-methyl ester, improves survival in anaphylactic shock. Eur J Pharmacol 203:125–127
Bogle RB, Moncada S, Pearson JD, Mann GE (1992) Identification of inhibitors of nitric oxide synthase that do not interact with the endothelial cell arginine transporter. Br J Pharmacol 105:768–770
Boje KM, Fung HL (1989) Endothelial nitric oxide generating enzyme(s) in the bovine aorta: subcellular location and metabolic characterization. J Pharmacol Exp Ther 253:20–26
Förstermann U, Schmidt HHHW, Pollock JS, Sheng H, Mitchell JA, Warner TD, Nakane M, Murad F (1991) Isoforms of nitric oxide synthase. Biochem Pharmacol 42:1849–1857
Furchtgott RF, Zawadzki JW (1980) The obligatory role of endothelial cells in the relaxation of endothelial smooth muscle by acetylcholine. Nature 288:373–376
Garg UC, Hassid A (1989) Nitric oxide generating vasodilators and 8-bromocyclic guanosine monophosphate inhibit mitogenesis and proliferation of cultured rat vascular smooth muscle cells. J Clin Invest 83:1774–1777
Garthwaite J, Charles SL, Chess-Williams R (1988) Endothelium-derived relaxing factor release on activation of NMDA receptors suggests role as intercellular messenger in the brain. Nature 336:385–387
Gillespie JS, Liu X, Martin W (1990) The neurotransmitter of the non-drenergic non-cholinergic inhibitory nerves to smooth muscle of the genital system In: Moncada S, Higgs EA (eds) Nitric oxide from L-arginine: a bioregulatory system. Elsevier, Amsterdam, pp 393–395
Hecker M, Mitchell JA, Harris HJ, Katsura M, Thiemermann C, Vane JR (1990) NG-monomethyl-L-arginine but not NW-nitro-L-arginine is metabolized by endothelial cells to L-citrulline. Eu J Pharmacol 183:648–649
Huber S, Grohs JG, Schwarzacher S, Raberger G (1992) Oral NG-nitro-L-arginine in conscious dogs: 24 hour hypertensive response in relation to plasma levels. Amino Acids 2:225–232
Ignarro LJ, Buga GM, Wood KS, Byrns RE, Chaduri G (1987) Endothelium-derived relaxing factor produced and released from artery and vein is nitric oxide. Proc Natl Acad Sci USA 84:9265–9269
Krejcy K, Schwarzacher S, Sexl V, Raberger G (1992) Different distribution of L-NG-nitro arginine and L-NG-nitro arginine methylester in canine blood. Naunyn-Schmiedebergs Arch Pharmacol 346:R35
Lambert LE, Whitten JP, Baron BM, Cheng HC, Doherty NS, McDonald IA (1991) Nitric oxide synthesis in the CNS, endothelium and macrophages differs in its sensitivity to inhibition by arginine analogues. Life Sci 48:69–75
Lewis MJ (1992) Nitric oxide and regulation of coronary vascular tone. Cardiovasc Res 26:555–556
Marletta MA, Yoon PS, Iyengar R, Leaf CD, Wishnok JS (1988) Macrophage oxidation of L-arginine to nitrite and nitrate: nitric oxide is an intermediate. Biochemistry 27:8706–8711
Moncada S, Palmer RMJ, Higgs EA (1991) Nitric oxide: physiology, pathophysiology, and pharmacology. Pharmacol Rev 43:109–142
Moore PK, Al-Swayeh OA, Chong NWS, Evans RA, Gibson A (1990) L-NG-nitro arginine (L-NOARG), a novel, L-arginine reversible inhibitor of endothelium-dependent vasodilation in vitro. Br J Pharmacol 99:408–412
Palmer RMJ, Ferrige AG, Moncada S (1987) Nitric oxide release accounts for the biological activity of endothelium-derived relaxing factor. Nature 327:524–526
Palmer RMJ, Ashton DS, Moncada S (1988a) Vascular endothelial cells synthesize nitric oxide from L-arginine. Nature 333:664–666
Palmer RMJ, Rees DD, Ashton DS, Moncada S (1988b) L-arginine is the physiological precursor for the formation of nitric oxide in endothelium-dependent relaxation. Biochem Biophys Res Commun 153:1251–1256
Pollock JS, Förstermann U, Mitchell JA, Warner TD, Schmidt HH, Nakane M, Murad F (1991) Purification and characterization of particulate endothelium-derived relaxing factor synthase from endothelial cells. Proc Natl Acad Sci USA 88:10480–10484
Radomski MW, Palmer RMJ, Moncada S (1987) Comparative pharmacology of endothelium derived relaxing factor, nitric oxide and prostacyclin in platelets. Br J Pharmacol 92:181–187
Rees DD, Palmer RMJ, Schulz R, Hodson HF, Moncada S (1990) Characterization of three inhibitors of endothelial nitric oxide synthase in vitro and in vivo. Br J Pharmacol 101:746–752
Remuzzi G, Perico N, Zoja C, Corna D, Macconi D, Vigano G (1990) Role of endothelium-derived nitric oxide in the bleeding tendency of uremia. J Clin Invest 86:1768–1771
Schmidt HHHW, Nau H, Wittfoht W, Gerlach J, Prescher KE, Klein MM, Niroomand F, Böhme E (1988) Arginine is a physiologic precursor of endothelium-derived nitric oxide. Eur J Pharmacol 154:213–216
Schmidt HHHW, Pollock JS, Nakane M, Gorsky LD, Förstermann U, Murad F (1991) Purification of a soluble isoform of guanylyl cyclase-activating-factor synthase. Proc Natl Acad Sci USA 88:365–369
Schwarzacher S, Raberger G (1992) L-NG-nitro-arginine methyl ester in the anaesthetized rabbit: venous vasomotion and plasma levels. J Vasc Res 29:290–292
Wright CE, Rees DD, Moncada S (1992) Protective and pathological roles of nitric oxide in endotoxin shock. Cardiovasc Res 26:48–57
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Some of the results have been presented at the Autumn Meeting of the German Society for Pharmacology and Toxicology in Graz 1992 (Krejcy et al. 1992)
Correspondence to K. Krejcy at the above address
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Krejcy, K., Schwarzacher, S. & Raberger, G. Distribution and metabolism of NG-nitro-L-arginine and NG-nitro-L-arginine methylester in canine blood in vitro. Naunyn-Schmiedeberg's Arch Pharmacol 347, 342–345 (1993). https://doi.org/10.1007/BF00167455
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DOI: https://doi.org/10.1007/BF00167455