S-nitrosoglutathione (GSNO) involved in storage and transport of nitric oxide (？NO) plays an important role in vascular homeostasis. Breakdown of GSNO can be catalyzed by γ-glutamyltransferase (GGT). We investigated whether vascular GGT influences the vasorelaxant effect of GSNO in isolated rat aorta. Histochemical localization of GGT and measurement of its activity were performed by using chromogenic substrates in sections and in aorta homogenates, respectively. The role of GGT in GSNO metabolism was evaluated by measuring GSNO consumption rate (absorbance decay at 334 nm), ？NO release was visualized and quantified with the fluorescent probe 4,5-diaminofluorescein diacetate. The vasorelaxant effect of GSNO was assayed using isolated rat aortic rings (in the presence or absence of endothelium). The role of GGT was assessed by stimulating enzyme activity with cosubstrate glycylglycine, as well as using two independent inhibitors, competitive serine borate complex and non-competitive acivicin. Specific GGT activity was histochemically localized in the endothelium. Consumption of GSNO and release of free ？NO decreased and increased in presence of serine borate complex and glycylglycine, respectively. In vasorelaxation experiments with endothelium-intact aorta, the half maximal effective concentration of GSNO (EC50 = 3.2±0.5.10？7 M) increased in the presence of the two distinct GGT inhibitors, serine borate complex (1.6±0.2.10？6 M) and acivicin (8.3±0.6.10？7 M), while it decreased with glycylglycine (4.7±0.9.10？8 M). In endothelium-denuded aorta, EC50 for GSNO alone increased to 2.3±0.3.10？6 M, with no change in the presence of serine borate complex. These data demonstrate the important role of endothelial GGT activity in mediating the vasorelaxant effect of GSNO in rat aorta under physiological conditions. Because therapeutic treatments based on GSNO are presently under development, this endothelium-dependent mechanism involved in the vascular effects of GSNO should be taken into account in a pharmacological perspective.
Ginnan R, Guikema BJ, Halligan KE, Singer HA, Jourd'heuil D (2008) Regulation of smooth muscle by inducible nitric oxide synthase and NADPH oxidase in vascular proliferative diseases. Free Radic Biol Med 44: 1232–45.
Krejcy K, Schmetterer L, Kastner J, Nieszpaur-Los M, Monitzer B, et al. (1995) Role of nitric oxide in hemostatic system activation in vivo in humans. Arterioscler Thromb Vasc Biol 15: 2063–7.
Arnold WP, Mittal CK, Katsuki S, Murad F (1977) Nitric oxide activates guanylate cyclase and increases guanosine 3′: 5′-cyclic monophosphate levels in various tissue preparations. Proc Natl Acad Sci USA 74: 3203–7.
Sogo N, Campanella C, Webb DJ, Megson IL (2000) S-nitrosothiols cause prolonged, nitric oxide-mediated relaxation in human saphenous vein and internal mammary artery: therapeutic potential in bypass surgery. Br J Pharmacol 131: 1236–44.
McAninly J, Williams DLH, Askew SC, Butler AR, Russell C (1993) Metal ion catalysis in nitrosothiol (RSNO) decomposition. J Chem Soc, Chem Commun 23: 1758–9.
Angeli V, Tacito A, Paolicchi A, Barsacchi R, Franzini M, et al. (2009) A kinetic study of gamma-glutamyltransferase (GGT)-mediated S-nitrosoglutathione catabolism. Arch Biochem Biophys 481: 191–6.
Hogg N, Singh RJ, Konorev E, Joseph J, Kalyanaraman B (1997) S-Nitrosoglutathione as a substrate for gamma-glutamyl transpeptidase. Biochem J 323: 477–81.
Cotgreave IA, Schuppe-Koistinen I (1994) A role for gamma-glutamyl transpeptidase in the transport of cystine into human endothelial cells: relationship to intracellular glutathione. Biochim Biophys Acta 1222: 375–82.
Dominici S, Pieri L, Comporti M, Pompella A (2003) Possible role of membrane gamma. glutamyltransferase activity in the facilitation of transferrin-dependent and -independent iron uptake by cancer cells. Cancer Cell Int 3: 7.
Lartaud I, Faure S, Tabellion A, Resende AC, Nadaud S, et al. (2007) Melatonin counteracts the loss of agonist-evoked contraction of aortic rings induced by incubation. Fundam Clin Pharmacol 21: 273–9.
Resende AC, Tabellion A, Nadaud S, Lartaud I, Bagrel D, et al. (2004) Incubation of rat aortic rings produces a specific reduction in agonist-evoked contraction: effect of age of donor. Life Sci 76: 9–20.
Tran NNP, Spitzbarth E, Robert A, Giummelly P, Atkinson J, et al. (1998) Nitric oxide lowers the calcium sensitivity of tension in the rat tail artery. J Physiol 507: 163–74.
Wang C, Mansard A, Giummelly P, Atkinson J (2004) Decreased aortic smooth muscle contraction in a rat model of multibacterial sepsis. Fundam Clin Pharmacol 18: 679–83.
Orlowski M, Meister A (1963) Gamma-glutamyl-p-nitroanilide: a new convenient substrate for determination and study of L- and D-gamma-glutamyltranspeptidase activities. Biochim biophys acta 73: 679–81.
Maguin Gate K, Lartaud I, Giummelly P, Legrand R, Pompella A, et al. (2011) Accurate measurement of reduced glutathione in gamma-glutamyltransferase-rich brain microvessel fractions. Brain Res 1369: 95–102.
Rodriguez J, Specian V, Maloney R, Jourd'heuil D, Feelisch M (2005) Performance of diamino fluorophores for the localization of sources and targets of nitric oxide. Free Radic Biol Med 38: 356–68.
Bramanti E, Angeli V, Franzini M, Vecoli C, Baldassini R, et al. (2009) Exogenous vs. endogenous gamma-glutamyltransferase activity: Implications for the specific determination of S-nitrosoglutathione in biological samples. Arch Biochem Biophys 487: 146–52.
Franzini M, Corti A, Martinelli B, Del Corso A, Emdin M, et al. (2009) Gamma-glutamyltransferase activity in human atherosclerotic plaques – Biochemical similarities with the circulating enzyme. Atherosclerosis 202: 119–27.
Gaucher C, Boudier A, Dahboul F, Parent M, Leroy P (2012) S-nitrosation/denitrosation in cardiovascular pathologies: facts and concepts for the rational design of S-nitrosothiols. Curr Pharm Des. In press.
Heikal L, Aaronson PI, Ferro A, Nandi M, Martin GP, et al. (2011) S-nitrosophytochelatins: investigation of the bioactivity of an oligopeptide nitric oxide delivery system. Biomacromolecules 12: 2103–13.
Nikitovic D, Holmgren A (1996) S-nitrosoglutathione is cleaved by the thioredoxin system with liberation of glutathione and redox regulating nitric oxide. J Biol Chem. 271: 19180–5.
Hanspal IS, Magid KS, Webb DJ, Megson IL (2002) The Effect of Oxidative Stress on Endothelium-Dependent and Nitric Oxide Donor-Induced Relaxation: Implications for Nitrate Tolerance. Nitric Oxide-Biol Ch 6: 263–70.
Corti A, Franzini M, Cianchetti S, Bergamini G, Lorenzini E, et al. (2012) Contribution by polymorphonucleate granulocytes to elevated gamma-glutamyltransferase in cystic fibrosis sputum. PLoS ONE 7(4): e34772.
Pompella A, Emdin M, Passino C, Paolicchi A (2004) The significance of serum gamma-glutamyltransferase in cardiovascular diseases. Clin Chem Lab Med 42: 1085–91.
Snyder AH, McPherson ME, Hunt JF, Johnson M, Stamler JS, et al. (2002) Acute effects of aerosolized -nitrosoglutathione in cystic fibrosis. Am J Respir Crit Care Med 165: 922–6.
Rassaf T, Poll LW, Brouzos P, Lauer T, Totzeck, et al (2006) Positive effects of nitric oxide on left ventricular function in humans. Eur Heart J 27: 1699–705.
