• Journal of Plant Biology
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• v.29 no.2
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• pp.85-94
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• 1986

Canavanine content of the cotyledons of Canavalia lineata decreased gradually during germination and growth of seedlings but continued to increase in roots and leaves. After abscission of cotyledons, canavanine content of leaves depleted competely. The activity of canavanase could be detected in leaves and roots, but not in cotyledons. High arginase activity was observed in the cotyledons of seeds at the earlyimbibition period. During the growth of seedlings, cotyledonary canavanine appeared to be transported to the growing of seedlings where it could be utilized through nitrogen metabolic pathways. In crude cell-free extracts of leaves, maximum activities of canavanase or arginase appeared in 30mM Tris-HCl buffer (pH 9.0) or 30mM NaHCO3 buffer (pH 10.0), respectively. The activities of these two enzymes differed from each other when treated with Co2+ or Mn2+. These results support the idea that canavanase and arginase might be different enzymes.

• BMB Reports
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• v.54 no.10
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• pp.516-521
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• 2021

Although arginase primarily participates in the last reaction of the urea cycle, we have previously demonstrated that arginase II is an important cytosolic calcium regulator through spermine production in a p32-dependent manner. Here, we demonstrated that rhaponticin (RPT) is a novel medicinal-plant arginase inhibitor and investigated its mechanism of action on Ca²⁺-dependent endothelial nitric oxide synthase (eNOS) activation. RPT was uncompetitively inhibited for both arginases I and II prepared from mouse liver and kidney. It also inhibited arginase activity in both aorta and human umbilical vein endothelial cells (HUVECs). Using both microscope and FACS analyses, RPT treatments induced increases in cytosolic Ca²⁺ levels using Fluo-4 AM as a calcium indicator. Increased cytosolic Ca²⁺ elicited the phosphorylations of both CaMKII and eNOS Ser1177 in a time-dependent manner. RPT incubations also increased intracellular L-arginine (L-Arg) levels and activated the CaMKII/AMPK/Akt/eNOS signaling cascade in HUVECs. Treatment of L-Arg and ABH, arginase inhibitor, increased intracellular Ca²⁺ concentrations and activated CaMKII-dependent eNOS activation in ECs of WT mice, but, the effects were not observed in ECs of inositol triphosphate receptor type 1 knockout (IP3R1^-/-) mice. In the aortic endothelium of WT mice, RPT also augmented nitric oxide (NO) production and attenuated reactive oxygen species (ROS) generation. In a vascular tension assay using RPT-treated aortic tissue, cumulative vasorelaxant responses to acetylcholine (Ach) were enhanced, and phenylephrine (PE)-dependent vasoconstrictive responses were retarded, although sodium nitroprusside and KCl responses were not different. In this study, we present a novel mechanism for RPT, as an arginase inhibitor, to increase cytosolic Ca²⁺ concentration in a L-Arg-dependent manner and enhance endothelial function through eNOS activation.

• Journal of Ginseng Research
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• v.14 no.1
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• pp.6-9
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• 1990

Specific activities of ADC and ODC from 2-4 year old ones were higher than that from seedlings whereas those activities were not changed significantly from 2 to 4 years. Generally, activity of ADC was predorminant compared to that of ODC. Free arginine content in roots was much higher than that of leaves. And arginase specific activity from roots was higher than that of leaves. Cumulative results suggest that putrscine formation from ornithine in roots may be more effective than leaves and contribute to putrescine biosynthesis to some extract.

• Proceedings of the Zoological Society Korea Conference
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• 1995.10b
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• pp.264.2-264
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• 1995

No Abstract, See Full Text

• Advances in Traditional Medicine
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• v.4 no.1
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• pp.9-17
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• 2004

The present investigation was under taken to study whether the tumor-associated macrophages (TAM) of Daltons lymphoma (DL), a spontaneous transplantable murine T cell lymphoma can be activated to tumoricidal state by crude thymus extract. Intraperitoneal administration of thymus extract to DL-bearing mice resulted in activation of TAM with an enhanced IL-1, TNF and antigen presenting ability. It was found that treatment with thymus extract could also enhance the phagocytic and cytotoxic activity of TAM. However, only a marginal increase in arginase activity was observed. Till date to the best of our knowledge the effect of crude thymus extract on the activation of tumor associated macrophages has not been investigated, this study provides a new piece of information in the area of thymus therapy.

• Bulletin of the Korean Chemical Society
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• v.33 no.9
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• pp.3079-3082
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• 2012

• Clinical and Experimental Reproductive Medicine
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• v.48 no.2
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• pp.124-131
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• 2021

Objective: Approximately 30% of preeclamptic pregnancies exhibit abnormal liver function tests. We assessed liver injury-associated enzyme levels and circulating transforming growth factor beta (TGF-β) levels in an arginine vasopressin (AVP)-induced pregnant Sprague-Dawley rat model. Methods: Pregnant and non-pregnant Sprague-Dawley rats (n=24) received AVP (150 ng/hr) subcutaneously via mini-osmotic pumps for 18 days. Blood pressure was measured, urine samples were collected, and all animals were euthanized via isoflurane. Blood was collected to measure circulating levels of TGF-β1-3 isomers and liver injury enzymes in pregnant AVP (PAVP), pregnant saline (PS), non-pregnant AVP (NAVP), and non-pregnant saline (NS) rats. Results: The PAVP group showed significantly higher systolic and diastolic blood pressure than both saline-treated groups. The weight per pup was significantly lower in the AVP-treated group than in the saline group (p<0.05). Circulating TGF-β1-3 isomer levels were significantly higher in the PAVP rats than in the NS rats. However, similar TGF-β1 and TGF-β3 levels were noted in the PS and PAVP rats, while TGF-β2 levels were significantly higher in the PAVP rats. Circulating liver-type arginase-1 and 5'-nucleotidase levels were higher in the PAVP rats than in the saline group. Conclusion: This is the first study to demonstrate higher levels of TGF-β2, arginase, and 5'-nucleotidase activity in PAVP than in PS rats. AVP may cause vasoconstriction and increase peripheral resistance and blood pressure, thereby elevating TGF-β and inducing the preeclampsia-associated inflammatory response. Future studies should explore the mechanisms through which AVP dysregulates liver injury enzymes and TGF-β in pregnant rats.

• Parasites, Hosts and Diseases
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• v.35 no.3
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• pp.189-196
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• 1997

The purpose of this study is to determine whether nitric oxide is involved in the extracellular killing of Trichomoncs uasinalis by mouse (BALB/c) peritoneal macrophages and RAW264.7 cells activated with LPS or rIFN-γ and also to observe the effects of various chemicals which affect the production of reactive nitrogen intermediates (RNl) in the cytotoxicity against T. vnginnlis. The cytotoxicity was measured by counting the release of (3H)-thymidine from labelled protozoa and NOa was assayed by Griess reaction. Nemonomethyl-L-arginine (L-NMHA), Nenitro-L-arginine methyl ester (NAME) and arginase inhibited cytotoxicity to T. vaginnlis and nitrite production by activated mouse perioneal macrophagrs and RAW 264.7 cells. The addition of excess L-arginine competitively restored trichomonacidal activity of macrophages. Exogenous addition of FeSO4 inhibited cytotoxicity to T. vaginaLis and nitric products of macrophages. From above results, it is assumed that nitric oxide plays an important role in the host defense mechanism of macrophages against T ucfinalis.

• Molecules and Cells
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• v.37 no.1
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• pp.66-73
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• 2014

Myeloid-derived suppressor cells (MDSCs) play an important role in impairing the function of T cells. We characterized MDSCs in two chronic hepatitis C (CHC) cohorts: a cross-sectional group that included 61 treatment-naive patients with CHC, 14 rapid virologic response (RVR) cases and 22 early virologic response (EVR) cases; and a longitudinal group of 13 cases of RVR and 10 cases of EVR after pegylated-interferon-${\alpha}$/ribavirin treatment for genotype 1b HCV infection. Liver samples from 32 CHC patients and six healthy controls were subjected to immunohistochemical analysis. MDSCs frequency in treatment-naive CHC was significantly higher than in RVR, EVR, or healthy subjects and was positively correlated with HCV RNA. Patients infected with HCV genotype 2a had a significantly higher frequency of MDSCs than those infected with genotype 1b. Decreased T cell receptor (TCR) ${\zeta}$ expression on $CD8^+$ T cells was significantly associated with an increased frequency of MDSCs in treatment-naive CHC patients and was restored by L-arginine treatment in vitro. Increased numbers of liver arginase-$1^+$ cells were closely associated with the histological activity index in CHC. The TCR ${\zeta}$ chain was significantly downregulated on hepatic $CD8^+$ T cells in CHC. During antiviral follow up, MDSCs frequency in peripheral blood mononuclear cells was directly correlated with the HCV RNA load in the plasma and inversely correlated with TCR ${\zeta}$ chain expression in $CD8^+$ T cells in both RVR and EVR cases. Notably, the RVR group had a higher frequency of MDSCs at baseline than the EVR group. Collectively, this study provides evidence that MDSCs might be associated with HCV persistence and downregulation of CD8 ${\zeta}$ chain expression.

• The Journal of Korean Medicine
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• v.21 no.3
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• pp.20-30
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• 2000

Objective : This experiment was performed in order to study the effect of an aqueous extract of Salviae radix root(SRRAE) on NO production and NOS gene induction from macrophages Methods : To investigate dose-dependent effects of SRRAE for NO release on the $rIFN-{\gamma}-treated$ macrophages, the cells were incubated for 6 hrs in a medium containing $rIFN-{\gamma}$ (5 U/ml), stimulated with SRRAE and incubated in a CO2 incubator. The cells were treated with 5 U/ml $rIFN-{\gamma}$ plus 100 g/ml of SRRAE, Then, the cells were incubated with various concentrations of NGMMA at $37^{\circ}C$ for 48 hrs, Results : SRRAE had no effect on NO production by itself, whereas recombinant $interferon-{\gamma}(rIFN-{\gamma})$ alone showed modest activity, When SRRAE was used in combination with $rIFN-{\gamma}$, there was a marked cooperative induction of NO production in a dose-dependent manner. The optimal effect of SRRAE on NO production was shown at 6hrs after treatment with $rIFN-{\gamma}$. The SRRAE-induced production of NO was inhibited by NG-monomethyl- L-arginine(NGMMA) and arginase. $rIFN-{\gamma}$ in combination with SRRAE showed a marked increase of the expression of the inducible NOS(iNOS) gene. In addition, the effect of SRRAE was mainly dependent on the SRRAE-induced tumor necrosis $factor-{\alpha}(TNF-{\alpha})$ secretion. Conclusions : SRRAE induces NO production from macrophages as a result of SRRAE-induced $TNF-{\alpha}$ secretion. SRRAE may provide a second signal for synergistic induction of NO production in macrophages already induced to express iNOS gene by $rIFN-{\gamma}$.