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Inhibition of arginase by in alveolar macrophages: implications for the utilization of l ‐arginine for nitric oxide synthesis
Author(s) -
Hecker Markus,
Nematollahi Heideh,
Hey Claudia,
Busse Rudi,
Racké Kurt
Publication year - 1995
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(95)00039-c
Subject(s) - arginase , nitric oxide , arginine , lipopolysaccharide , nitric oxide synthase , chemistry , biochemistry , ic50 , lysis , biosynthesis , alveolar macrophage , macrophage , pulmonary alveolus , microbiology and biotechnology , in vitro , biology , enzyme , immunology , amino acid , organic chemistry
The hypothesis was investigated that the nitric oxide (NO) synthase intermediate, (HOArg), is an arginase inhibitor in rabbit or rat alveolar macrophages. Exogenously applied HOArg strongly inhibited the arginase activity present in these cells (IC 50 ≥ 15 μ M), and attenuated l ‐[ 3 H]arginine transport (IC 50 ≥ 500 μ M) in rabbit alveolar macrophages. Moreover, up to 37 μM HOArg were detected in the conditioned medium, but not in the lysate, of rat alveolar macrophages exposed to bacterial lipopolysaccharide for 18 h. HOArg may thus be a potent endogenous arginase inhibitor in these cells which increases the availability of l ‐arginine for NO biosynthesis.