Exogenous NG‐hydroxy‐l‐arginine causes nitrite production in vascular smooth muscle cells in the absence of nitric oxide synthase activity

FEBS Letters

Bogen, C.M.¹  Stoclet, J.C.¹  Vetrovsky, P.¹  Berton, C.C.¹  Schott, C.A.¹ 

[1] Université Louis Pasteur de Strasbourg, Laboratoire de Pharmacologie Cellulaire et Moléculaire, CNRS URA600, B.P. 24, 67401 Illkirch, France

关键词: N G-Hydroxy-l-arginine;    Smooth muscle cell;    Nitric oxide;    NO-synthase;    Arginine uptake;    OH-l-Arg;    N G-hydroxy-l-arginine;    l-NAME;    N G-nitro-l-arginine methyl ester;    LPS;    lipopolysaccharide;    HBSS;    Hank's balanced salt solution;    NO;    nitric oxide;   

DOI  :  10.1016/0014-5793(94)80457-5

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Nitric oxide (NO) production from exogenous N ^G-hydroxy-l-arginine (OH-l-Arg) was investigated in rat aortic smooth muscle cells in culture by measuring nitrite accumulation in the culture medium. As well, the interaction between OH-l-Arg and l-arginine uptake via the y⁺ cationic amino acid transporter was studied. In cells without NO-synthase activity, OH-l-Arg (1–1000 μM) induced a dose-dependent nitrite production with a half-maximal effective concentration (EC₅₀) of 18.0 ± 1.5 μM (n = 4–7). This nitrite accumulation was not inhibited by the NO-synthase inhibitor N _G-nitro-l-arginine methyl ester, l-NAME (300 μM). In contrast, it was abolished by miconazole (100 μM), an inhibitor of cytochrome P₄₅₀. Incubation of vascular smooth muscle cells with LPS (10 ) induced an l-name inhibited nitrite accumulation, but did not enhance the OH-l-Arg induced nitrite production. OH-l-Arg and other cationic amino acids, L-lysine and l-ornithine, competitively inhibited [³H]-l-arginine uptake m rat aortic smooth muscle cells, with inhibition constants of 195 ± 23 μM(n = 12), 260 ± 40 μM(n= 5) and 330 ± 10 μM(n = 5), respectively. These results show that OH-l-Arg is recognized by the cationic l-amino acid carrier present in vascular smooth muscle cells and can be oxidized to NO and nitrite in these cells in the absence of NO-synthase, probably by cytochrome P₄₅₀ or by a reaction involving a cytochrome P₄₅₀ byproduct.

【 授权许可】

Unknown