Ornithine Levels Research Articles

The effect of “Remivital” on plasma amino acid composition in dairy cows with ketosis

Aim. To investigate plasma amino acid composition in dairy cows after ketosis conventional (oral administra- tion of propylene glycol, intravenous injection of glucose and insulin) and proposed treatment (oral administra- tion of propylene glycol, intravenous injection of “Remivital”). Methods. Study was performed on high yield- ing dairy cows with clinical ketosis during their 2 nd to 4 th lactation with milk yield above 8000 L per previous lactation. Content of free amino acids was determined in plasma before and after treatment using amino acid analyzer. Results. Lowering of the level of ketogenic amino acids was revealed after conducted treatment as well as increase in the level of glycogenic and branched amino acids. Signifi cant lowering of the level of meth- ylhistidine gives evidence of decreased catabolism of contractile proteins. Conclusions. Proposed treatment regimen has proven to be superior, since signifi cantly higher level of ornithine and lower level of citrulline were revealed after administration of conventional regimen, which gives evidence of problems in disposal of ammonia and lactate. Moreover, in case of administration of traditional scheme, the concentration of markers of catabolism of contractile proteins was still high, in contrast with such in animals, which were administered proposed regimen, and high concentration of isoleucine contributes to aggravation of ketoacidosis.

The Increase in Liver Polyamine Concentration Contributes to the Tryptophan‐induced Stimulation of Hepatic Protein Synthesis

Tryptophan has a unique role as a nutritional signaling molecule that regulates protein synthesis in mice and rat liver. However, the mechanism of the stimulating actions of tryptophan on hepatic protein synthesis has not been clearly elucidated. Tryptophan has been suggested to stimulate protein synthesis at the translational level, because polysome aggregation was observed in a short time after oral administration of tryptophan. Therefore, we focused on the acute effects of tryptophan on protein synthesis. In the present study, proteomic and metabolomic analysis was performed to identify candidate proteins and metabolites, which are likely to play a role in stimulation of protein synthesis by tryptophan. Eighteen hours fasted Wistar rats were divided into 3 groups. One group of animals was sacrificed without any treatment as a control. Remaining two groups of animals were administered 135mg/100g body weight L‐tryptophan by oral gavage and then sacrificed after 1h or 3h after administration. With two‐dimensional electrophoresis and image analysis, four differentially expressed protein spots were detected at 3h after administration of tryptophan, and one of which was identified as key enzyme in the biosynthetic pathway of ornithine, ornithine aminotransferase (OAT) precursor. OAT is the main catabolic enzyme of ornithine and its expression was significantly decreased by tryptophan administration. The concentration of ornithine was increased in both serum and liver at 3h after administration of tryptophan. Ornithine is a precursor for polyamine biosynthesis. Ornithine decarboxylase (ODC) catalyzes the first step in the polyamine biosynthetic pathway forming putrescine, which is then converted into the polyamines spermidine and spermine. It has been reported that oral administration of tryptophan to overnight‐fasted rats exhibited increase in the hepatic ODC activity. Significantly increased concentrations of polyamines, as well as ornithine were found in the liver at 3h after administration of tryptophan. Based on these results, we speculate that the increase in ornithine level through suppression of OAT expression and stimulation of ODC activity by tryptophan administration may lead to accelerated polyamine synthesis and thereby promote protein synthesis in the liver.

Longitudinal plasma metabolic profiles, infant feeding, and islet autoimmunity in the MIDIA study.

The aim of this study was to investigate the longitudinal plasma metabolic profiles in healthy infants and the potential association with breastfeeding duration and islet autoantibodies predictive of type 1 diabetes. Up to four longitudinal plasma samples from age 3 months from case children who developed islet autoimmunity (n = 29) and autoantibody-negative control children (n = 29) with the HLA DR4-DQ8/DR3-DQ2 genotype were analyzed using two-dimensional gas chromatography coupled to a time-of-flight mass spectrometer for detection of small polar metabolites. Plasma metabolite levels were found to depend strongly on age, with fold changes varying up to 50% from age 3 to 24 months (p < 0.001 after correction for multiple testing). Tyrosine levels tended to be lower in case children, but this was not significant after correction for multiple testing. Ornithine levels were lower in case children compared with the controls at the time of seroconversion, but the difference was not statistically significant after correcting for multiple testing. Breastfeeding for at least 3 months as compared with shorter duration was associated with higher plasma levels of isoleucine, and lower levels of methionine and 3,4-dihydroxybutyric acid at 3 months of age. Plasma levels of several small, polar metabolites changed with age during early childhood, independent of later islet autoimmunity status and sex. Breastfeeding was associated with higher levels of branched-chain amino acids, and lower levels of methionine and 3,4-dihydroxybutyric acid.

Ornithine is a key mediator in hyperphosphatemia-mediated human umbilical vein endothelial cell apoptosis: Insights gained from metabolomics

AimsHyperphosphatemia is associated with accelerated vascular endothelial dysfunction in patients with chronic kidney disease (CKD). The purpose of this study is to investigate the molecular mechanisms underlying hyperphosphatemia-caused endothelial dysfunction. Main methodsThe metabolic fingerprinting of human umbilical vein endothelial cells (HUVECs) subjected to hyperphosphatemia was characterized using an integrated metabolomics approach. HUVECs cultured in physiologically simulated hyperphosphatemia with or without phosphonoformic acid, a sodium-dependent phosphate transporter inhibitor (N=6) were collected for metabolomics analysis. Multivariate principle component analysis and partial least squares discriminant analysis were applied to analyze the metabolic data. The key metabolites were confirmed by quantitative analysis using liquid chromatography coupled with tandem mass spectrometer (LC–MS/MS). Key findings36 metabolites were significantly altered in HUVECs following the challenges of hyperphosphatemia mimic, involving several metabolic pathways (all P<0.05). Among them, ornithine increased significantly in the HUVECs mediated by hyperphosphatemia mimic, and its levels positively correlated with cell apoptosis rate (r=0.674, P=0.002), and several additional metabolites in multiple metabolic pathways. The changes in the levels of ornithine and other several metabolites were supported by subsequent quantitative analyses using LC–MS/MS. Further study demonstrated that the increase in ornithine level may result from the increased expression of arginase 2 in HUVECs, which mediates the hydrolysis of arginine to form ornithine. SignificanceThis is the first study demonstrating ornithine a key molecule mediating hyperphosphatemia-induced apoptosis of ECs. Arginase 2 may be a therapeutic target for hyperphosphatemia-associated cardiovascular events.

Lysozyme affects the microbial catabolism of free arginine in raw-milk hard cheeses

Lysozyme (LZ) is used in several cheese varieties to prevent late blowing which results from fermentation of lactate by Clostridium tyrobutyricum. Side effects of LZ on lactic acid bacteria population and free amino acid pattern were studied in 16 raw-milk hard cheeses produced in eight parallel cheese makings conducted at four different dairies using the same milk with (LZ+) or without (LZ-) addition of LZ. The LZ-cheeses were characterized by higher numbers of cultivable microbial population and lower amount of DNA arising from lysed bacterial cells with respect to LZ + cheeses. At both 9 and 16 months of ripening, Lactobacillus delbrueckii and Lactobacillus fermentum proved to be the species mostly affected by LZ. The total content of free amino acids indicated the proteolysis extent to be characteristic of the dairy, regardless to the presence of LZ. In contrast, the relative patterns showed the microbial degradation of arginine to be promoted in LZ + cheeses. The data demonstrated that the arginine-deiminase pathway was only partially adopted since citrulline represented the main product and only trace levels of ornithine were found. Differences in arginine degradation were considered for starter and non-starter lactic acid bacteria, at different cheese ripening stages.

Changes in the metabolome of rats after exposure to arginine and N-carbamylglutamate in combination with diquat, a compound that causes oxidative stress, assessed by 1H NMR spectroscopy.

Numerous factors can induce oxidative stress in animal production and lead to growth retardation, disease, and even death. Arginine and N-carbamylglutamate can alleviate the effects of oxidative stress. However, the systematic changes in metabolic biochemistry linked to oxidative stress and arginine and N-carbamylglutamate treatment remain largely unknown. This study aims to examine the effects of arginine and N-carbamylglutamate on rat metabolism under oxidative stress. Thirty rats were randomly divided into three dietary groups (n = 10 each). The rats were fed a basal diet supplemented with 0 (control), 1% arginine, or 0.1% N-carbamylglutamate for 30 days. On day 28, the rats in each treatment were intraperitoneally injected with diquat at 12 mg per kg body weight or sterile solution. Urine and plasma samples were analyzed by metabolomics. Compared with the diquat group, the arginine + diquat group had significantly lower levels of acetamide, alanine, lysine, pyruvate, tyrosine, α-glucose, and β-glucose in plasma; N-carbamylglutamate + diquat had higher levels of 3-hydroxybutyrate, 3-methylhistidine, acetone, allantoin, asparagine, citrate, phenylalanine, trimethylamine-N-oxide, and tyrosine, and lower levels of low density lipoprotein, lipid, lysine, threonine, unsaturated lipid, urea, and very low density lipoprotein (P < 0.05) in plasma. Compared with the diquat group, the arginine + diquat group had significantly higher levels of citrate, creatinine, homogentisate, and α-ketoglutarate while lower levels of acetamide, citrulline, ethanol, glycine, isobutyrate, lactate, malonate, methymalonate, N-acetylglutamate, N-methylnicotinamide, propionate, and β-glucose (P < 0.05) in urine. Compared with the diquat group, the N-carbamylglutamate + diquat group had significantly higher levels of allantoin, citrate, homogentisate, phenylacetylglycine, α-ketoglutarate, and β-glucose while lower levels of acetamide, acetate, acetone, benzoate, citrulline, ethanol, hippurate, lactate, N-acetylglutamate, nicotinamide, ornithine, and trigonelline (P < 0.05) in urine. Overall, these results suggest that arginine and N-carbamylglutamate can alter the metabolome associated with energy metabolism, amino acid metabolism, and gut microbiota metabolism under oxidative stress.

Ultra-wide Field Imaging of an Operated Macular Hole in Gyrate Atrophy.

Medical records of a 46‐year‐old woman with bilateral myopia, gyrate atrophy, and history of night blindness were reviewed. The patient underwent macular hole surgery in the left eye 3 years back. The surgery consisted of pars plana vitrectomy (PPV), induction of posterior vitreous detachment (PVD), internal limiting membrane (ILM) peeling, and fluid‐air exchange. She had serum ornithine level of 784 nmole/ml and a best‐corrected visual acuity (BCVA) of 1/60 (with correcting lens of −7.25D) in the left eye preoperatively with early posterior subcapsular cataract and a large macular hole (diameter :1254 μm; Cirrus HD‐OCT, Carl Zeiss Meditec, Dublin, CA, USA) with round localized neurosensory retinal detachment at the posterior pole. At month 3 after the operation, 6/60 vision (with correcting lens of ‐8.00‐1.00×100) in the left eye was documented, which remained unchanged. Six months after the operation, she underwent cataract surgery with implantation of a posterior chamber intraocular lens in the capsular bag in the left eye. At the last follow up examination, 3 years after PPV, intraocular pressure in both eyes was normal, and there was no squint. BCVA was 6/9 in the right eye (with correcting lens of ‐9.00‐3.00×90) and 6/60 in the left eye (with correcting lens of −3D). Fundus examination showed typical coalescent areas of scalloped chorioretinal atrophy in both eyes [Figures 1 and 2]. Right eye had central macular thickness of 151 μm in optical coherence tomography (OCT, Cirrus HD‐OCT, Carl Zeiss Meditec, Dublin, CA, USA) without any evidence Ultra‐wide Field Imaging of an Operated Macular Hole in Gyrate Atrophy

Effect of a traditional Chinese medicine prescription Quzhuotongbi decoction on hyperuricemia model rats studied by using serum metabolomics based on gas chromatography-mass spectrometry.

Morbidity of hyperuricemia has constantly increased in population in decades, and hyperuricemia has proved to be an important risk factor for gout, cardiovascular diseases and others. Many urate-lowering drugs have unfavorable side effects and drug interactions. Quzhuotongbi decoction (QZTBD) is an empirical traditional Chinese medicine prescription for clinical therapy of hyperuricemia without serious adverse effects. In the study, we investigated the effects of QZTBD on urate and other metabolites in the sera of hyperuricemia model rats. Hyperuricemia model was established by orally administering yeast extract paste, and allopurinol served as a positive control drug. Serum metabolomics was performed by using a gas chromatography-mass spectrometry (GC-MS) method. Student's t-test and the principal component analysis (PCA) were employed to find the metabolic perturbations in hyperuricemia model rats. The levels of urate, lactate, pyruvate and ornithine were significantly increased, and xanthine, glyconic acids (ribonate, galactonate), amino acids (aspartate, proline, glutamine, serine, pyroglutamate, glutamate) and glucose were down-regulated greatly in the model rats. It demonstrated that nucleotide metabolism, amino acid metabolism and glycolytic pathway were disturbed by yeast administration. An orthogonal signal correction-partial least-squares discriminant analysis (OSC-PLS DA) was performed to assess the effects of yeast administering and drug treatment. 11 significantly distinctive metabolites among four groups were defined according to the variable importance for project values (VIP>1) and univariate ANOVA (p value<0.05). As compared to the model rats, the serum uric acid levels were lowered markedly under the treatment of allopurinol or QZTBD. Aspartate and glutamine involved in purine metabolism, were raised to normal level as well. The different influences on xanthine, glutamate pyroglutamate and galactonate suggested there were different mechanisms of two drugs in urate-lowering therapy. Our finding proved that QZTBD can efficiently lower the level of serum uric acid in a different way from allopurinol, which suggested that QZTBD based on the theory of TCM could be an effective therapeutic option for hyperuricemia.

Capillary electrophoresis reveals polyamine metabolism modulation in Leishmania (Leishmania) amazonensis wild-type and arginase-knockout mutants under arginine starvation.

l-Arginine is an essential amino acid in Leishmania (Leishmania) amazonensis metabolism. A key enzyme for parasite l-arginine metabolism is arginase (ARG) that uses arginine to produce urea and ornithine, a precursor of polyamine pathway guaranteeing parasite replication in both insect and mammal hosts. There is an alternative pathway to produce ornithine via l-proline and glutamate, but this mechanism is not described in Leishmania. In the mammal host, two enzymes can use l-arginine as substrate, the host ARG and the induced nitric oxide synthase that produces nitric oxide. The competition between induced nitric oxide synthase and both parasite and host ARG can favor the success of the infection or its control. Here, we established the metabolomics profile of the polyamine pathway of wild type (WT) L. (L.) amazonensis, submitted or not to l-arginine starvation, and compared to the ARG-knockout mutant (arg- ). Our results indicated that arginine starvation induces a decrease in arginine, ornithine, and putrescine, but we could not detect the significative level changes of spermidine, spermine, or agmatine. However, the absence of ARG on the arg- induced an increase of arginine and citrulline levels, but decreased the levels of ornithine and putrescine. Similarly to the WT arginine-starved parasites, the arg- parasites presented lower levels of proline when compared to the WT ones. This could be indicative of an alternative pathway to surpass the enzyme or its substrate absence.

PTH-200 Amino acid profiles in patient with intestinal failure: preliminary data on biochemical insights

<h3>Introduction</h3> Amino acid profiles have become increasingly important in intestinal failure (IF), ever since citrulline has been used as an IF marker. The purpose of the present study is to investigate levels in patients with IF needing parenteral nutrition (PN) and to examine their use as markers of IF severity to guide clinical decisions. <h3>Method</h3> Serum amino acids levels were measured prospectively within the cohort of patients managed by the IF Unit at our hospital using Ion Exchange Chromatography. Statistical analysis was performed by R and SPSS 21.0 using Pearson’s Correlation coefficient, t-tests and ANOVA. The traditional classification of IF¹was taken as a proxy of IF severity where Type 1 IF was coded as 1 and type 3 IF was coded as 3. <h3>Results</h3> Our study included 35 patients (11 Males, mean age 45, range 16–87), non IF controls (n = 10), Type 1 IF (n = 3), Type 2 IF (n = 3), Type 3 IF (n = 19); all IF patients were on PN. Causes of IF were short bowel syndrome, enterocutaneous fistula, high stoma output, pseudo-obstruction and radiation enteropathy. Citrulline was significantly lower in patients with Type 3 IF (p = 0.033) and receiving PN (p = 0.031) compared to other groups. Valine was significantly lower in patients with Type 3 and 2 IF compared to other controls and type 1 (p = 0.053); a trend was observed for lower homocysteine in patients receiving PN (p = 0.082). The other amino acids didn’t display differences with respects to groups. Figure 1 shows the correlation matrix between amino acids levels and severity of IF. Lower levels of citrulline, valine, alanine, total homocysteine, methionine, histidine, ornithine, and isoleucine were associated with more severe IF (range of correlation coefficients –0.432 to –0.174) whilst glutamate levels had a positive association (0.215) with less severe IF. Strong positive associations were found between amino acids valine, histidine, threonine, methionine, ornithine, alanine, leucine and isoleucine (correlation coefficient range 0.41–0.73), suggesting involvement in common biochemical pathways. <h3>Conclusion</h3> The present study confirmed the usefulness of citrulline as a marker of enterocytes mass in IF It provided new evidence that lower levels of valine, total homocysteine, methionine, histidine, ornithine, and isoleucine were associated with more severe IF. Larger studies are needed to validate those data. <h3>Disclosure of interest</h3> None Declared. <h3>Reference</h3> ESPEN endorsed recommendations. Definition and classification of intestinal failure in adults. <i>Clin Nutr</i>. 2014. doi: 10.1016/j.clnu.2014.08.017

Alteration of ornithine metabolism leads to dominant and recessive hereditary spastic paraplegia.

Hereditary spastic paraplegias are heterogeneous neurological disorders characterized by a pyramidal syndrome with symptoms predominantly affecting the lower limbs. Some limited pyramidal involvement also occurs in patients with an autosomal recessive neurocutaneous syndrome due to ALDH18A1 mutations. ALDH18A1 encodes delta-1-pyrroline-5-carboxylate synthase (P5CS), an enzyme that catalyses the first and common step of proline and ornithine biosynthesis from glutamate. Through exome sequencing and candidate gene screening, we report two families with autosomal recessive transmission of ALDH18A1 mutations, and predominant complex hereditary spastic paraplegia with marked cognitive impairment, without any cutaneous abnormality. More interestingly, we also identified monoallelic ALDH18A1 mutations segregating in three independent families with autosomal dominant pure or complex hereditary spastic paraplegia, as well as in two sporadic patients. Low levels of plasma ornithine, citrulline, arginine and proline in four individuals from two families suggested P5CS deficiency. Glutamine loading tests in two fibroblast cultures from two related affected subjects confirmed a metabolic block at the level of P5CS in vivo. Besides expanding the clinical spectrum of ALDH18A1-related pathology, we describe mutations segregating in an autosomal dominant pattern. The latter are associated with a potential trait biomarker; we therefore suggest including amino acid chromatography in the clinico-genetic work-up of hereditary spastic paraplegia, particularly in dominant cases, as the associated phenotype is not distinct from other causative genes.

AmcA-a putative mitochondrial ornithine transporter supporting fungal siderophore biosynthesis.

Iron is an essential nutrient required for a wide range of cellular processes. The opportunistic fungal pathogen Aspergillus fumigatus employs low-molecular mass iron-specific chelators, termed siderophores, for uptake, storage and intracellular iron distribution, which play a crucial role in the pathogenicity of this fungus. Siderophore biosynthesis (SB) depends on coordination with the supply of its precursor ornithine, produced mitochondrially from glutamate or cytosolically via hydrolysis of arginine. In this study, we demonstrate a role of the putative mitochondrial transporter AmcA (AFUA_8G02760) in SB of A. fumigatus. Consistent with a role in cellular ornithine handling, AmcA-deficiency resulted in decreased cellular ornithine and arginine contents as well as decreased siderophore production on medium containing glutamine as the sole nitrogen source. In support, arginine and ornithine as nitrogen sources did not impact SB due to cytosolic ornithine availability. As revealed by Northern blot analysis, transcript levels of siderophore biosynthetic genes were unresponsive to the cellular ornithine level. In contrast to siderophore production, AmcA deficiency did only mildly decrease the cellular polyamine content, demonstrating cellular prioritization of ornithine use. Nevertheless, AmcA-deficiency increased the susceptibility of A. fumigatus to the polyamine biosynthesis inhibitor eflornithine, most likely due to the decreased ornithine pool. AmcA-deficiency decreased the growth rate particularly on ornithine as the sole nitrogen source during iron starvation and sufficiency, indicating an additional role in the metabolism and fitness of A. fumigatus, possibly in mitochondrial ornithine import. In the Galleria mellonella infection model, AmcA-deficiency did not affect virulence of A. fumigatus, most likely due to the residual siderophore production and arginine availability in this host niche.

The genetic diversity of cystinuria in a UK population of patients.

To examine the genetic mutations in the first UK cohort of patients with cystinuria with preliminary genotype/phenotype correlation. DNA sequencing and multiplex ligation-dependent probe amplification (MLPA) were used to identify the mutations in 74 patients in a specialist cystinuria clinic in the UK. Patients with type A cystinuria were classified into two groups: Group M patients had at least one missense mutation and Group N patients had two alleles of all other types of mutations including frameshift, splice site, nonsense, deletions and duplications. The levels of urinary dibasic amino acids, age at presentation of disease, number of stone episodes and interventions were compared between patients in the two groups using the Mann-Whitney U-test. In all, 41 patients had type A cystinuria, including one patient with a variant of unknown significance and 23 patients had type B cystinuria, including six patients with variants of unknown significance. One patient had three sequence variants in SLC7A9; however, two are of unknown significance. Three patients had type AB cystinuria. Three had a single mutation in SLC7A9. No identified mutations were found in three patients in either gene. There were a total of 88 mutations in SLC3A1 and 55 mutations in SLC7A9. There were 23 pathogenic mutations identified in our UK cohort of patients not previously published. In patients with type A cystinuria, the presence of a missense mutation correlated to lower levels of urinary lysine (mean [SE] 611.9 [22.65] vs 752.3 [46.39] millimoles per mole of creatinine [mM/MC]; P=0.02), arginine (194.8 [24.83] vs 397.7 [15.32] mM/MC; P<0.001) and ornithine (109.2 [7.40] vs 146.6 [12.7] mM/MC; P=0.02). There was no difference in the levels of urinary cystine (182.1 [8.89] vs 207.2 [19.23] mM/MC; P=0.23). We have characterised the genetic diversity of cystinuria in a UK population including 23 pathogenic mutations not previously published. Patients with at least one missense mutation in SLC3A1 had significantly lower levels of lysine, arginine, and ornithine but not cystine than patients with all other combinations of mutations.

Involvement of the Putative N-Acetylornithine Deacetylase from Arabidopsis thaliana in Flowering and Fruit Development.

In eukaryotic cells, the non-proteinogenic amino acid ornithine is the precursor of arginine and polyamines (PAs). The final step of ornithine biosynthesis occurs in plants via a cyclic pathway catalyzed by N(2)-acetylornithine:N-acetylglutamate acetyltransferase (NAOGAcT). An alternative route for ornithine formation, the linear pathway, has been reported for enteric bacteria and a few other organisms; the acetyl group of N(2)-acetylornithine is released as acetate by N(2)-acetylornithine deacetylase (NAOD). NAOD activity has never been demonstrated in plants, although many putative NAOD-like genes have been identified. In this investigation, we examined the effect of down-regulation of the putative Arabidopsis thaliana NAOD gene by using AtNAOD-silenced (sil#17) and T-DNA insertional mutant (atnaod) plants. The ornithine content was consistently reduced in sil#17 and atnaod plants compared with wild-type plants, suggesting that in addition to NAOGAcT action, AtNAOD contributes to the regulation of ornithine levels in plant cells. Ornithine depletion was associated with altered levels of putrescine and spermine. Reduced AtNAOD expression resulted in alterations at the reproductive level, causing early flowering and impaired fruit setting. In this regard, the highest level of AtNAOD expression was observed in unfertilized ovules. Our findings suggest that AtNAOD acts as a positive regulator of fruit setting and agree with those obtained in tomato auxin-synthesizing parthenocarpic plants, where induction of SlNAOD was associated with the onset of ovary growth. Thus, here we have uncovered the first hints of the functions of AtNAOD by connecting its role in flower and fruit development with the regulation of ornithine and PA levels.

Effect of rosuvastatin on arginase enzyme activity and polyamine production in experimental breast cancer.

Breast cancer is the most common malignant tumour of women around the world. As a key enzyme of the urea cycle, arginase leads to the formation of urea and ornithine from L-arginine. In the patients with several different cancers, arginase has been found to be higher and reported to be a useful biological marker. The aim of this study was to investigate the effect of rosuvastatin on serum and cancer tissue arginase enzyme activity, and ornithine and polyamine (putrescine, spermidine, spermine) levels. Animal experiment. In this study, 50 male Balb/c mice were used. Erchlich acid tumour cells were injected into the subcutaneous part of their left foot. The mice were divided into five groups: healthy control group, healthy treatment, tumour control, treatment 1 and treatment 2. Then, 1 mg/kg and 20 mg/kg doses of rosuvastatin were given intraperitoneally. Serum and tissue arginase enzyme activities and tissue ornithine levels were determined spectrophotometrically. HPLC measurement of polyamines were applied. Increased serum arginase activity and polyamine levels were significantly decreased with rosuvastatin treatment. In the tumour tissue, arginase activity and ornithine levels were significantly decreased in treatment groups compared to the tumour group. Tissue polyamine levels also decreased with rosuvastatin treatment. We suggest that rosuvastatin may have some protective effects on breast cancer development as it inhibits arginase enzyme activity and ornithine levels, precursors of polyamines, and also polyamine levels. This protective effect may be through the induction of nitric oxide (NO) production via nitric oxide synthase (NOS). As a promising anticancer agent, the net effects of rosuvastatin in this mechanism should be supported with more advanced studies and new parameters.

Arginine-Restricted Therapy Resistant Bilateral Macular Edema Associated with Gyrate Atrophy.

Introduction. Gyrate atrophy is a rare genetical metabolic disorder affecting vision. Here, we report a 9-year-old boy with gyrate atrophy associated with bilateral macular edema at the time of diagnosis and the effect of long term metabolic control on macular edema. Case Presentation. A 9-year-old boy presented with a complaint of low visual acuity (best corrected visual acuity: 20/80 in both eyes, refractive error: −12.00 D). Dilated fundus examination revealed multiple bilateral, sharply defined, and scalloped chorioretinal atrophy areas in the midperipheral and peripheral zone. Spectral-domain optical coherence tomography revealed bilateral cystoid macular edema in both eyes. Serum ornithine level was high (622 μmol/L). An arginine-restricted diet reduced serum ornithine level (55 μmol/L). However, visual findings including macular edema remained unchanged in 2 years of follow-up. Conclusion. Arginine-restricted diet did not improve macular edema in our patient with gyrate atrophy. A more comprehensive understanding of the underlying factors for macular edema will lead to the development of effective therapies.

Polyamine biosynthesis and degradation are modulated by exogenous gamma-aminobutyric acid in root-zone hypoxia-stressed melon roots

We detected physiological change and gene expression related to PA metabolism in melon roots under controlled and hypoxic conditions with or without 5 mM GABA. Roots with hypoxia treatment showed a significant increase in glutamate decarboxylase (GAD) activity and endogenous GABA concentration. Concurrently, PA biosynthesis and degradation accelerated with higher gene expression and enzymes activity. However, endogenous GABA concentrations showed a large and rapid increase in Hypoxia + GABA treated roots. This led to a marked increase in Glu concentration by feedback inhibition of GAD activity. Hypoxia + GABA treatment enhanced arginine (Arg), ornithine (Orn) and methionine (Met) levels, promoting enzyme gene expression levels and arginine decarboxylase (ADC), ornithine decarboxylase (ODC) and S-adenosylmethionine decarboxylase (SAMDC) activities in roots. Hypoxia + GABA treatment significantly increased concentrations of free putrescine (Put), spermidine (Spd) and spermine (Spm) from day two to eight, promoting the PA conversion to soluble conjugated and insoluble bound forms. However, PA degradation was significantly inhibited in hypoxia + GABA treated roots by significantly decreasing gene expression and activity of diamine oxidase (DAO) and polyamine oxidase (PAO). However, exogenous GABA showed a reduced effect in control compared with hypoxic conditions. Our data suggest that alleviating effect of exogenous GABA to hypoxia is closely associated with physiological regulation of PA metabolism. We propose a potential negative feedback mechanism of higher endogenous GABA levels from combined effects of hypoxia and exogenous GABA, which alleviate the hypoxia damage by accelerating PA biosynthesis and conversion as well as preventing PA degradation in melon plants.

Dietary arginine requirement of juvenile grass carpCtenopharyngodon idella(Valenciennes in Cuvier &amp; Valenciennes, 1844)

This experiment was conducted to estimate the optimum requirement of arginine for juvenile grass carp Ctenopharyngodon idella. Six isonitrogenous (38%) and isoenergetics (16 MJ kg−1) semi-purified diets containing casein and gelatine with graded level of arginine (0.93, 1.20, 1.51, 1.84, 2.10 and 2.41 g 100 g−1 DM) were formulated. Each diet was randomly assigned to triplicate groups of 25 fish each tank (initial weight: 3.84 ± 0.01) for 10 weeks. The highest weight gain (WG, %) was recorded when arginine level was 2.10% of the diet. Dietary arginine level higher than 1.84% significantly increased the protein contents of whole body. Whole body amino acid composition of juvenile grass carp was not significantly affected by the dietary arginine level. Plasma-free arginine level was increased linearly with increasing of arginine level in the diets, and the plasma-free ornithine level was significantly higher when the dietary arginine level was 2.41% compared with other groups. Quadratic model analysis of SGR data indicated that the minimum recommended dietary arginine requirement for grass carp was 2.17% of the diet, corresponding to 5.71% of dietary protein.

Kimchi fermented in a kimchi refrigerator showed enhanced anti‐cancer effects on human leukemia and gastric cancer cells (LB405)

In this study we investigated the anticancer effects of Kimchi (DV) extract obtained from Baechu kimchi fermented and stored in a kimchi refrigerator for 21 days. The DV kimchi extract contained higher levels of ornithine compared with control kimchi (DS) extract obtained from standard storage condition. The DV kimchi significantly inhibited the proliferation of both AGS (human, gastric adenocarcinoma) and HL‐60 (human, acute promyelocytic leukemia) cell lines. The DV kimchi extract treatment lead to increased apoptosis and decreased mitochondrial transmembrane potential in the cultured HL‐60 leukemia cells. In addition, the treatments resulted in increased expression of the p53 gene in cultured AGS gastric adenocarcinoma cells. On the other hand, the DS kimchi treatments showed relatively a small effect on the cancer cell growth prevention, apoptosis, and mitochondrial transmembrane potential at the similar concentration ranges of kimchi extract. These results suggest that, the consumption of DV kimchi could be more beneficial in promoting apoptosis and retarding the proliferation of cancer cells compared to the DS kimchi. This research was funded by WiniaMando Inc.

Angiotensin II‐induced arterial fibrosis and stiffness is prevented in arginase 1‐deficient mice (1065.8)

Arterial stiffness (AS) is an independent risk factor for cardiovascular morbidity and mortality. Increases in smooth muscle cell (SMC) proliferation and collagen synthesis are key features in development of AS. Arginase (ARG), an enzyme implicated in many cardiovascular diseases and fibrosis, can compete with nitric oxide (NO) synthase for their common substrate, L‐arginine. Increased ARG, in addition to reducing NO production, can also elevate levels of ornithine for synthesis of polyamines via ornithine decarboxylase (ODC) and proline/collagen via ornithine aminotransferase (OAT), leading to increases in cell proliferation and collagen formation, respectively. In order to investigate the role of ARG1 in AS, wild type (WT) or ARG1 KO mice were infused with angiotensin II (Ang II, 4 wks). Ang II infusion in WT mice increased levels of aortic ARG activity/expression, ODC mRNA, hydroxyproline, type I collagen, fibrosis, and induced AS (as shown by increased pulse wave velocity). These effects did not occur in Ang II infused ARG1 KO mice. Exposure of rat aortic SMCs to Ang II (1 μM, 48 hrs) increased ARG activity (57%), cell proliferation (22%), type 1 collagen protein (44%), ODC mRNA (25%), and hydroxyproline (22%). Treatment with ARG inhibitor ABH prevented these changes. In summary, ARG1 is crucially involved in arterial SMC proliferation, fibrosis and stiffness and represents a promising therapeutic target.