The Urea Cycle in Different Types of Macrophages

Hofmann, Friedrich; Kreusch, Jürgen; Maier, K. P.; Munder, P. G.; Decker, Karl

doi:10.1042/bst0060990

Cited by 20 publications

(23 citation statements)

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“…Our present results indicate that J774 cells can synthesize L-[14C]-arginine from L-["'-C]-citrulline, which is increased further following activation of J774 cells with LPS and IFN-y. These findings suggest that the enzymatic pathway, arginosuccinate synthase/lyase (Hoffman et al, 1978), responsible for citrulline metabolism is induced by treatment of J774 cells with these agents. Wu & Brosnan (1992) have reported a 3 fold increase in the metabolism of citrulline to arginine in LPStreated rat peritoneal macrophages.…”

Section: Selectivity Of Citrulline Transportmentioning

confidence: 86%

Discrimination between citrulline and arginine transport in activated murine macrophages: inefficient synthesis of NO from recycling of citrulline to arginine

Baydoun

Bogle

Pearson

et al. 1994

British J Pharmacology

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1 The kinetics, specificity, pH-and Na'-dependency of L-citrulline transport were examined in unstimulated and lipopolysaccharide (LPS)-activated murine macrophage J774 cells. The dependency of nitric oxide production on extracellular arginine or citrulline was investigated in cells activated with LPS (lg fgml') for 24h. 2In unstimulated J774 cells, transport of citrulline was saturable (K, = 0.16 mM and Vm.u 32 pmol pg' protein min-'), pH-insensitive and partially Na'-dependent. In contrast to arginine, transport of citrulline was unchanged in LPS-activated (1 jg ml-', 24 h) cells. 3 Kinetic inhibition experiments revealed that arginine was a relatively poor inhibitor of citrulline transport, whilst citrulline was a more potent inhibitor (Ki = 3.4 mM) of arginine transport but only in the presence of extracellular Na'. Neutral amino acids inhibited citrulline transport (Ki = 0.2-0.3 mM), but were poor inhibitors of arginine transport. 4 Activated J774 cells did not release nitrite in the absence of exogenous arginine. Addition of citrulline (0.01-10 mM), in the absence of exogenous arginine, could only partially restore the ability of cells to synthesize nitrite, which was abolished by 100 pM NG-nitro-L-arginine methyl ester or NG-]-arginine was detected in unstimulated J774 cells and was increased further in cells activated with LPS and interferon-y. 6 We conclude that J774 macrophage cells transport citrulline via a saturable but nonselective neutral carrier which is insensitive to induction by LPS. In contrast, transport of arginine via the cationic amino acid system y+ is induced in J774 cells activated with LPS. 7 Our findings also confirm that citrulline can be recycled to arginine in activated J774 macrophage cells. Although this pathway provides a mechanism for enhanced arginine generation required for NO production under conditions of limited arginine availability, it cannot sustain maximal rates of NO synthesis.

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Section: Selectivity Of Citrulline Transportmentioning

confidence: 86%

Discrimination between citrulline and arginine transport in activated murine macrophages: inefficient synthesis of NO from recycling of citrulline to arginine

Baydoun

Bogle

Pearson

et al. 1994

British J Pharmacology

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“…A proportion of this product is further metabolized to NO and citrulline whereas a considerable amount of OHArg is secreted together with NO as an adduct [7]. OH-Arg is a strong inhibitor of arginase [15,16] an enzyme constitutively present in macrophages [17]. Several biological effects have been ascribed to OH-Arg including modulation of blood pressure and tumor cell cytostasis [3,14].…”

Section: Discussionmentioning

confidence: 99%

Oxidation of N^G‐hydroxyl‐l‐arginine to nitric oxide mediated by respiratory burst: an alternative pathway to NO synthesis

1997

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A^-Hydroxy-L-arginine is an intermediate metabolite in the synthesis of nitric oxide that is upregulated and secreted during acute inflammation in vivo. Previous reports have shown that chemically induced Superoxide anion oxidizes A^-hydroxy-L-arginine to nitric oxide. Here, we demonstrate that this reaction takes place physiologically in phagocytic cells during the respiratory burst, and is independent of the presence of nitric oxide synthase.

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“…19 On the other hand, phosarginase appears to be expressed constitutively in phodiesterase (PDE) inhibitors, and in particular the different types of M including AM of all species inhibitors of PDE4, a cAMP-specific isoform, 20 play studied so far. 2,[6][7][8][9] In mammals two isoforms of aran increasing role in the treatment of inflammatory ginase (I and II) have been identified (for reviews see and obstructive airway diseases. 21,22 Since AM play 10,11 ) and the pattern of their expression in M appears an important role in the local control of inflammatory to vary in a species-and/or M type-dependent manreactions and specific immune responses 23 and since ner.…”

Section: Introductionmentioning

confidence: 99%

Phosphodiesterase Inhibitors and Forskolin Up-regulate Arginase Activity in Rabbit Alveolar Macrophages

Hammermann

Hey

Schäfer

et al. 2000

Pulmonary Pharmacology & Therapeutics

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The Urea Cycle in Different Types of Macrophages

Cited by 20 publications

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Discrimination between citrulline and arginine transport in activated murine macrophages: inefficient synthesis of NO from recycling of citrulline to arginine

Discrimination between citrulline and arginine transport in activated murine macrophages: inefficient synthesis of NO from recycling of citrulline to arginine

Oxidation of N^G‐hydroxyl‐l‐arginine to nitric oxide mediated by respiratory burst: an alternative pathway to NO synthesis

Phosphodiesterase Inhibitors and Forskolin Up-regulate Arginase Activity in Rabbit Alveolar Macrophages

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The Urea Cycle in Different Types of Macrophages

Cited by 20 publications

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Discrimination between citrulline and arginine transport in activated murine macrophages: inefficient synthesis of NO from recycling of citrulline to arginine

Discrimination between citrulline and arginine transport in activated murine macrophages: inefficient synthesis of NO from recycling of citrulline to arginine

Oxidation of NG‐hydroxyl‐l‐arginine to nitric oxide mediated by respiratory burst: an alternative pathway to NO synthesis

Phosphodiesterase Inhibitors and Forskolin Up-regulate Arginase Activity in Rabbit Alveolar Macrophages

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Oxidation of N^G‐hydroxyl‐l‐arginine to nitric oxide mediated by respiratory burst: an alternative pathway to NO synthesis