Citrulline Levels Research Articles

Plasma metabolomic profiles as affected by diet and stress in Spanish goats

The effects of high-condensed tannin (CT) diet combined with preslaughter stress have not been studied at the metabolome level in goats. This study was conducted to determine the effects of feeding sericea lespedeza (SL; Lespedeza cuneata), a high-CT legume, and transportation stress on plasma metabolome in goats. Uncastrated male Spanish goats (age = 8 months; BW = 26.0 ± 0.48 kg) were either fed ground ‘Serala’ SL hay (SER), bermudagrass (Cynodon dactylon) hay (BG), or bermudagrass hay-dewormed goats (BG-DW; Control) at 75% of intake, with a corn-based supplementation (25%) for 8 weeks (n = 12/Diet). At the end of the trial, goats were subjected to one of two stress treatments (ST): transported for 90 min to impose stress (TS) or held in pens (NTS) before slaughtering, in two replicates. Live and carcass weights, and blood samples were collected at 0, 30, 60 and 90 min of transportation or holding time (Time). The data were analyzed using MIXED procedures in SAS and metabolomics data were analyzed using the R software. When measured after ST, SER group had the lowest body weight (P < 0.05) among the three diet groups. Carcass weights were high in the BG-DW, low in SER, and intermediate in BG group. Plasma creatine concentrations decreased over Time (P < 0.01) in the TS goats in all diet groups. Meat crude protein percentages were higher (P < 0.05) in SER (22.5 ± 0.22) and BG-DW (22.3 ± 0.22) groups compared to the BG group (21.6 ± 0.22). At the metabolome level, SER group had the lowest (P < 0.05) glycine, alanine, threonine, taurine, trans-hydroxyproline, methionine, and histidine concentrations and highest (P < 0.01) lysine and citrulline concentrations among the Diet groups. Butyric acid, concentration was higher (P < 0.05) in the SER group compared to BG group. Eight medium- and long-chained acylcarnitines were higher (P < 0.05) in the BG-DW group than SER or BG groups. In general, amino acid levels decreased and acylcarnitine increased with Time (P < 0.05) in all groups. Sericea diet can be beneficial in enhancing stress coping abilities in goats due to elevated butyrate, lysine, and citrulline levels; however, SER resulted in lower energy level in goats compared to BG or BG-DW groups. Fatty acid metabolism is the main energy pathway in all groups during prolonged stress. Inclusion of certain varieties of SL in the diet must be carefully controlled to prevent possible negative effect.

New ratio as a useful marker for early diagnosis of proximal urea cycle disorders

Background and aimsProximal urea cycle disorders (PUCDs) are not included in most newborn screening programs due to the lack of adequate markers to monitor. Failure to alter citrulline and glutamine levels, the prognostic markers commonly used, can results in high false negative. Therefore, new biomarkers, prognostic of PUCDs, are strongly desirable. Materials and methodsWe used tandem mass spectrometry to analyze blood spot from PUCDs patients during their follow up in our referral center focusing on glutamine to glutamate (Gln/Glu) ratio. We reanalyzed the same specimens of three patients after two months and the specimen of a new patient with suspicious of PUCD disorder. ResultsSpecimens of our patients shown a significant elevation of the ratio Gln/Glu compared to that of a healthy population (p < 0.05) as well as the specimens analyzed after two months, while the glutamine concentration dropped. New patient, showing high value of the ratio, was molecularly confirmed as PUCD patient. We further analyzed the blood spots from a neonatal population in order to fix a cut-off value and include it in a newborn screening panel. ConclusionOur preliminary results suggest that the Gln/Glu ratio could be a very useful diagnostic marker, more stable over time than glutamine, which could improve the performance in early PUCDs identification.

Gene Expression Profiling in Liver of Mice Fed a High-Fat Diet Supplemented With Watermelon Flesh, Arginine, or Citrulline Shows Similar Pattern Changes

Abstract Objectives Watermelon is a nutrient-dense fruit known to contain high levels or arginine and citrulline; these two compounds may influence the nitric oxide pathway, vasodilation, and thus be hypotensive. We tested the hypothesis that when C57BL/6J male mice fed a high-fat diet (HF) had additions to the HF diet of either watermelon flesh (WF), arginine (ARG) or citrulline (CIT), changes in gene expression patterns would occur vs. those seen in HF. Further, we hypothesize that patterns of expression seen in WF, ARG, and CIT groups would be somewhat similar based on increased dietary levels of ARG and CIT in all three groups. Methods Following prior work (Becraft et al.; 2018, Egea et al. 2020), groups of mice were provided either a low-fat diet (LF, 10% kcal fat), high-fat diet (HF, 45% kcal fat), HF plus Watermelon Flesh (WF), HF plus 1% (w/w) arginine (ARG) or 1% (w/w citrulline (CIT) for 10 weeks. Watermelon flesh was provided at 10% of total energy. After ten weeks, animals were euthanized, and liver total RNA was isolated using Trizol. Total RNA was then used for gene expression analysis (N = 4 per group) using Clariom S microarrays and TAC analysis software (ThermoFisher). Results Mice fed WF, ARG, and CIT had several shared canonical pathways of gene expression, including eicosanoid metabolism via cytochrome P450 monooxygenases and exercise-induced circadian rhythm (All P &amp;lt; 0.05). Intake of WF and ARG significantly up-regulated both Cyp2c9 and Cyp2c38 mRNA levels (P &amp;lt; 0.05). The Bst2 gene was significantly down-regulated in all three groups compared to HF mice (P &amp;lt; 0.05). The Cyp2b9 gene was upregulated ∼10.7 fold in WF, and &amp;gt; 1000-fold in ARG mice (P &amp;lt; 0.05). Conclusions We demonstrated that when added to a HF diet, WF, ARG, and CIT all produced a change in hepatic gene expression in male mice. Possibly due to the close relationship of ARG and CIT metabolism, and high content of ARG and CIT in WF, expression patterns observed in all three groups demonstrated a high degree of similarity. Several genes, including Cyp2c9, Cyp2c38, and Elvol5 were up-regulated; these genes may be involved in modifying steroids and arachidonic acid and other long-chain fatty acids. Funding Sources National Watermelon Promotion Board.

Amino acid differences between diabetic older adults and non-diabetic older adults and their associations with cardiovascular function

BackgroundAgeing and insulin resistant states such as diabetes mellitus frequently coexist and increase the risk of cardiovascular disease development among older adults. Here we investigate metabolic differences in amino acid profiles between ageing and diabetes mellitus, and their associations with cardiovascular function. MethodsIn a group of community older adults we performed echocardiography, cardiac magnetic resonance imaging as well as cross sectional and longitudinal metabolomics profiling based on current and archived sera obtained fifteen years prior to examination. ResultsWe studied a total of 515 participants (women 50%, n = 255) with a mean age 73 (SD = 4.3) years. Diabetics had higher alanine (562 vs 448, p < 0.0001), higher glutamate (107 vs 95, p = 0.016), higher proline (264 vs 231, p = 0.008) and lower arginine (107 vs 117, p = 0.043), lower citrulline (30 vs 38, p = 0.006) levels (μM) compared to non-diabetics. Over time, changes in amino acid profiles differentiated diabetic older adults from non-diabetic older adults, with greater accumulation of alanine (p = 0.002), proline (p = 0.008) and (non-significant) trend towards greater accumulation of glycine (p = 0.057) among the older diabetics compared to the older non-diabetics. However, independent of diabetes status, amino acids were associated with cardiovascular functions in ageing, [archived valine (p = 0.011), leucine (p = 0.011), archived isoleucine (p = 0.0006), archived serine (p = 0.008), archived glycine (p = 0.006) methionine (p = 0.003)] which were associated with impairments in E/A ratio. ConclusionMarkers of branched chain amino acids and one ‑carbon metabolism pathways were associated with changes in cardiovascular function in older adults regardless of diabetes status. However, nitrogen handling pathways were specifically altered among older adults with diabetes. These findings broaden our understanding into specific amino acid pathways that may be altered between diabetic and non-diabetic older adults, and their relevance to cardiovascular function in ageing.Trial registration: ClinicalTrials.gov Identifier: NCT02791139

Liquid chromatography-mass spectrometry based metabolic characterization of pleural effusion in patients with acquired EGFR-TKI resistance

Epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) acquired resistance remains a major barrier in the clinical treatment of lung adenocarcinoma with epidermal growth factor receptor (EGFR) mutations. Despite extensive efforts, mechanism of acquired resistance has not yet been elucidated clearly. The subject of this study was to characterize the metabolic signatures relevant to acquired EGFR-TKI resistance in pleural effusion (PE), and identify potential biomarkers in PE of patients with acquired EGFR-TKI resistance. PE from EGFR-TKI untreated group (n = 30) and EGFR-TKI resistant group (n = 18) was analyzed using liquid chromatography-mass spectrometry (LCMS) based metabolomic. Multivariate statistical analysis revealed distinctive diff ;erences between the groups. A total of 34 significantly differential metabolites in PE were identified, among which, the acquired EGFR-TKI resistant group had higher levels of l-lysine, taurine, ornithine and citrulline, and lower levels of l-tryptophan, kynurenine, l-phenylalanine, l-leucine, N-formyl-l-methionine, 3-hydroxyphenylacetic acid and N-acetyl-d-phenylalanine in PE than that of the EGFR-TKI untreated group. These metabolites are mainly involved in six amino acid metabolic pathways. In addition, 3-hydroxyphenylacetic acid and N-acetyl-d-phenylalanine showed the highest AUC values of 0.934 and 0.929 in receiver operating characteristic analysis. Through LCMS metabolomics, our study identified potential biomarkers in PE, differentiating EGFR-TKI resistant patients from untreated patients, as well as the mechanisms underlying acquired EGFR-TKI resistance; thus, providing novel insights into acquired EGFR-TKI resistance.

The Correlation Between Decreased Ornithine Level and Alleviation of Rheumatoid Arthritis Patients Assessed by a Randomized, Placebo-Controlled, Double-Blind Clinical Trial of Sinomenine

Sinomenine (SIN) is commonly used as part of rheumatoid arthritis (RA) therapy in China, but there is still no published evidence of the efficacy of SIN monotherapy. This work investigates the efficacy and safety of SIN in treating RA patients and analyzes the correlation between ornithine level and the alleviation of disease activity in RA patients. In this 24 week, randomized, placebo-controlled, double-blind clinical trial, people with mild to moderate RA were randomly assigned (1:1:1, stratified by hospital) to receive SIN (120 mg, twice daily), methotrexate (MTX) (10 mg per week), or SIN + MTX therapy. The primary outcome was the proportion of patients who achieved a 50% improvement in the American College of Rheumatology (ACR50) criteria at week 24 and who showed improvement according to the clinical disease activity index (CDAI). In this prospective subgroup analysis, we also assessed whether the 24-week alterations of disease activity in the treatment group were significantly correlated to the levels of blood ornithine. Of the 135 enrolled participants, 38, 39, and 36 patients were treated with SIN, MTX, and SIN + MTX, respectively. In the SIN-treated group, 52.63% of patients achieved ACR50 after 24-weeks of treatment, which was comparable to the results in the MTX-treated and SIN + MTX-treated groups. Hepatic and gastrointestinal disorders were the main adverse events; however, the ratio of patients suffering from hepatic disorder in the SIN group (1/38) was much lower than that in the MTX (10/39) and SIN + MTX (8/36) groups. A total of 221 serum samples were collected at the four follow-up time points in the three treatments, and the levels of ornithine, citrulline, and arginine were obtained through ultra-high performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UHPLC-Q-TOF/MS). The serum ornithine level decreased after the 24-week treatment along with a decrease in disease activity, and may reflect therapeutic responses with a sensitivity value of 80%. In conclusion, SIN revealed a comparable efficacy to MTX for treating RA patients, but with fewer side effects. In addition, the serum ornithine level was found for the first time to have a close correlation with the alleviation of RA, which shows the value of this measure as an assessment indicator of drugs in treating RA.

Ornithine Transcarbamylase Deficiency Presenting with Symptoms of Mania in a Young Adult Male

The purpose of this case study is to review the clinical presentation and medical workup of a young adult male presenting with acute behavior changes in the setting of undiagnosed ornithine transcarbamylase deficiency (OTCD). This case study involves a 19-year-old male with a psychiatric history of depression and one previous suicide attempt, who presented to a large midwestern university hospital emergency department after being found by police naked in a neighbor's yard. He displayed manic signs and symptoms, including euphoria, lack of sleep for five days, and attempting to purchase a new car and three large screen TVs. Family reported the patient uncharacteristically announced three weeks earlier that he was vegetarian and stopped eating his frequent customary cheeseburgers. Due to increased anxiety and inability to sleep, the patient received lorazepam 2 mg in the emergency department. Upon transfer to the psychiatric unit, therapy was initiated with aripiprazole 5 mg daily and valproate 1000 mg nightly on Day 1 of treatment. The patient refused medications on hospital Day 2, then received this combination again on Day 3. The next morning, the patient complained of lethargy, headache, nausea, and vomiting. The patient's ammonia level was found to be 204 micromol/L with ALT and AST of 714 and 647 IU/L respectively. Tests for infectious hepatitis were negative. Medical consultation recommended discontinuation of current medications, vigorous hydration, and further work up. On further investigation, the patient was found to have low plasma citrulline level of 8 micromol/L, undetectable plasma arginine, and high urinary orotic acid. The laboratory data showed a biochemical phenotype consistent with a diagnosis of partial OTCD, an X-linked urea cycle disorder resulting in toxic hyperammonemia. The patient was treated with a low protein diet modification as well as a combination of sodium benzoate and sodium phenylbutyrate to reduce serum ammonia concentration. With treatment the patient's laboratory values normalized, and mental status improved. In conclusion, partial ornithine transcarbamylase deficiency may manifest with psychiatric symptoms in early adulthood. In young patients with elevated ammonia and mental status change, OTCD is an important diagnosis to consider, as it is the most common inherited cause of hyperammonemia.

Altered methylarginine levels after surgery in subjects with multinodular goiter.

Thyroid disorders are important risk factor for cardiovascular diseases. Levels of methylarginines such as asymmetric dimethyl arginine (ADMA), L-monomethyl arginine (L-NMMA), symmetric dimethyl arginine (SDMA) are increase in cardiovascular diseases. Multinodular goiter (MNG) is the most common type of goiter in adults. To date, no study has been conducted to determine the levels of methylarginine in euthyroid MNG patients. Our aim in this study is to compare levels of methylarginines and related metabolites in the preoperative, postoperative MNG patients and controls. Serum ADMA, SDMA, L-NMMA, homoarginine (hArg), arginine and citrulline concentrations were measured by liquid chromatography-tandem mass spectrometry (LC-MS/MS). ADMA (p<0.001), L-NMMA (p=0.002), l-arginine (p=0.006) and citrulline (p<0.001) levels were statistically significantly higher in preop group than postop group. ADMA (p=0.003), L-NMMA (p=0.003) levels were statistically significantly higher and SDMA/ADMA (p<0.001), hArg/ADMA (p<0.001) levels were statistically significantly lower in preop group than control group. The levels of methylarginines and related metabolites altered in the euthyroid MNG patients compared to the control group, and more importantly, there were significant differences between the preop and postop groups. Therefore, these metabolites can be useful in the diagnosis and prognosis of thyroid disorders, even if thyroid hormone levels are normal.

The variation in the levels of 18 amino acids in the cortex and plasma of cerebral ischemia C57BL/6 mice.

Emerging evidence suggests that amino acid (AA) neurotransmitters play important roles in the pathophysiological processes of cerebral ischemia. In this work, an HPLC with fluorescence detection (HPLC-FLR) method was developed for the simultaneous determination of 18 AAs in the cortex and plasma after cerebral ischemia in mice. The ischemia model was prepared by bilateral common carotid artery occlusion, and then the cortex and plasma of the sham, ischemia, and naringenin groups were collected. Based on the protein precipitation method, a simple and effective sample preparation method was developed. The treated sample contained minimal proteins and lipids. The analysis of the sample was performed by the proposed HPLC-FLR method in combination with o-phthalaldehyde. The results showed a statistically significant increase in excitatory AAs (aspartic acid and glutamic acid), inhibitory AAs (glycine and 4-aminobutyric acid), phenylalanine, citrulline, isoleucine, and leucine levels, and a decrease of glutathione and phenylalanine levels when compared with the sham group in the cortex. Besides, the administration of naringenin had significant effects on excitatory AAs, inhibitory AA (glycine), glutamine, tyrosine, phenylalanine, and leucine levels when compared with the sham group in the cortex. These findings could be utilized in studying and clarifying the mechanisms of ischemia.

SPG9A with the new occurrence of an ALDH18A1 mutation in a CMT1A family with PMP22 duplication: case report

BackgroundALDH18A1 mutations lead to delta-1-pyrroline-5-carboxylate-synthetase (P5CS) deficiency, which is a urea cycle-related disorder including SPG9A, SPG9B, autosomal dominant cutis laxa-3 (ADCL3), and autosomal recessive cutis laxa type 3A (ARCL3A). These diseases exhibit a broad clinical spectrum, which makes the diagnosis of P5CS deficiency difficult. We report here a rare Japanese family including both patients with an ALDH18A1 mutation (SPG9A) and ones with CMT1A.Case presentationA Japanese family included five patients with the CMT phenotype and five with the HSP phenotype in four generations. The patients with the HSP phenotype showed a pure or complicated form, and intrafamilial clinical variability was noted. Genetically, FISH analysis revealed that two CMT patients had a PMP22 duplication (CMT1A). Exome analysis and Sanger sequencing revealed five HSP patients had an ALDH18A1 heterozygous mutation of c.755G > A, which led to SPG9A. Haplotype analysis revealed that the ALDH18A1 mutation must have newly occurred. To date, although de novo mutations of ALDH18A1 have been described in ADCL3A, they were not mentioned in SPG9A in earlier reports. Thus, this is the first SPG9A family with a de novo mutation or the new occurrence of gonadal mosaicism of ALDH18A1. Analysis of serum amino acid levels revealed that two SPG9A patients and two unaffected family members had low citrulline levels and one had a low level of ornithine.ConclusionsSince the newly occurring ALDH18A1 mutation, c.755G > A, is the same as that in two ADHSP families and one sporadic patient with SPG9A reported previously, this genomic site might easily undergo mutation. The patients with the c.755G > A mutation in our family showed clinical variability of symptoms like in the earlier reported two families and one sporadic patient with this mutation. Further studies are required to clarify the relationship between the amino acid levels and clinical manifestations, which will reveal how P5CS deficiency influences disease phenotypes including ARCL3A, ADCL3, SPG9B, and SPG9A.

Screening for and combining serum intestinal barrier-related biomarkers to predict the disease severity of AECOPD

In the patients with AECOPD, the gut displays ischemia, anoxia and oxidative stress, which lead to the intestinal barrier failure. Therefore, it is desirable to screen for effective intestinal barrier-related biomarkers to monitor the disease severity. We conducted a prospective observational study in 40 patients with AECOPD and 10 patients with stable COPD. The serum levels of I-FABP, citrulline, D-Lactate, DAO, and α-GST, as well as the APACHE II scores were recorded. Person correlation analysis, logistic regression models and receiver operating characteristic (ROC) curve analyses were used in our study. Patients with AECOPD had significantly higher levels of I-FABP, D-Lactate, and DAO than did those with stable COPD. However, the serum citrulline level was significantly decreased in the patients with stable COPD than in those with AECOPD and the serum α-GST was not significantly changed. Additionally, we observed that there was a higher levels of I-FABP, D-Lactate, and DAO and a lower level of citrulline in patients with severe COPD than in patients with nonsevere COPD [APACHE II (nonsevere COPD) <20; APACHE II (severe COPD) ≥20]. Correlation analysis showed that I-FABP and D-Lactate had a significantly positive correlations with the APACHE II score, and citrulline had a significantly negative correlations with the APACHE II score. Following, treatment, the levels of I-FABP and D-lactate were decreased and the level of citrulline was increased. Moreover, we screened out the citrulline and DAO, which independently affected the diagnosis of severe COPD by stepwise logistics regression analysis. Additionally, we found that the combination of serum citrulline and DAO can more effectively diagnose the severe COPD than any single biomarker can, which may be a supportive and convenient method that can be used clinically. Serum I-FABP, citrulline and D-Lactate could be used to assess the disease severity. Citrulline and DAO can diagnose the severe COPD and the combination is more effective.

Association of proton pump inhibitor use with endothelial function and metabolites of the nitric oxide pathway: A cross-sectional study.

Long-term intake of proton pump inhibitors (PPIs) might increase the risk of cardiovascular events. One suggested mechanism is that PPIs inhibit the enzyme dimethylarginine dimethylaminohydrolase (DDAH) and thereby block the degradation of endothelial asymmetrical dimethylarginine (ADMA). Excess ADMA in turn leads to impaired endothelial nitric oxide (NO) generation. So far, this mechanism has only been established in human cell cultures. Previous studies that examined this pathway in human populations measured circulating ADMA and found no association with PPI use and excess plasma ADMA. But in a recent study, plasma ADMA was not correlated with intracellular ADMA. We therefore focused on changes in plasma citrulline as an indicator for potential DDAH inhibition. We analyzed the association between regular daily PPI intake and flow-mediated dilation (FMD) of the brachial artery as well as plasma concentrations of citrulline, arginine, ADMA, and symmetric dimethylarginine using inverse probability weighting to adjust for confounding and censoring. Data of 1298 participants from two independent cohorts of the population-based Study of Health in Pomerania were used. Participants of the population-based Study of Health in Pomerania are a stratified random sample of the study region. Regular daily intake of PPIs. FMD of the brachial artery and plasma concentrations of citrulline, arginine, ADMA, and symmetric dimethylarginine. Eighty-seven participants (57.5% female) were regular daily users of PPIs. In the fully adjusted models, associations were identified for FMD and plasma citrulline concentrations. PPI users revealed a 0.99% (95% CI: -1.96 to -0.02) lower FMD and 3.03µmol/L (95% CI: -4.96 to -1.10) lower plasma citrulline levels as compared to non-users. Our data provide evidence that long-term intake of PPIs might inhibit human DDAH activity, resulting in impaired endothelial NO production and reduced vascular function. In the long run, this might explain an increased risk for cardiovascular diseases associated with long-term PPI use.

Is there a relation between serum methylarginine levels and infertility?

Infertility is defined as the absence of pregnancy within the reproductive period despite regular sexual intercourse. Methylarginines are formed as a result of methylation of arginine residues in proteins and formed in three forms as asymmetric dimethyl arginine (ADMA), symmetrical dimethyl arginine (SDMA) and monomethylarginine (L-NMMA). So, here, we aimed to evaluate arginine and their derivatives levels in fertile and infertile individuals. Present study were consist of 30 oligozoospermia patients (proven by spermiogram analysis) and 30 healthy individuals with normozoospermia group who were applied to the urology department. With blood samples taken from individuals, serum methylarginine and its derivatives levels were analyzed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Clinic data and demographic characteristics of individuals were also recorded at the same time. The serum ADMA level (0.38±0.07) of the oligozoospermia group was found to be significantly higher than the normozoospermia group (0.35±0.05) (p=0.046). A positive correlation were observed between ADMA and SDMA (r=0.686, p=0.000), HArg and SDMA (r=0.611, p=0.001), citrulline and L-NMMA (r=0.595, p=0.001) in patients with oligosospermia. The increase in SDMA, arginine and HArg levels and a decrease in L-NMMA and citrulline levels were not significant as statistically. Also, the ADMA level was found to be high in individuals with low sperm concentration. Consequently, serum ADMA levels of individuals with oligozoospermia were statistically significantly higher than those with normozoospermia. As proposal, determination of ADMA levels may be a potential biomarker parameter in terms of early diagnosis of fertility and infertility.

Serum ADMA levels were positively correlated with EDSS scores in patients with multiple sclerosis

Multiple sclerosis (MS) is an autoinflammatory, chronic central nervous system disease. In the pathogenesis of the disease increased nitric oxide (NO) levels play an important role. Nitric oxide (NO) has neuroprotective effects in physiological conditions, however, it is thought that excessive NO formation in MS may lead to demyelination and axonal damage. Derivatives of methylarginine including asymmetric dimethyl arginine (ADMA), L-N monomethyl arginine (L-NMMA), symmetric dimethyl arginine (SDMA) directly or indirectly reduce NO production. Our aim was to measure the levels of methylarginine derivatives and citrulline, ornithine, arginine, homoarginine levels, which are metabolites associated with NO metabolism, in MS subgroups.

Effects of rumen-protected arginine supplementation on the plasma amino acids and gut microbiota of sika deer (Cervus nippon)

In this study, we examined the effects of rumen-protected arginine on antler growth, plasma biochemical values and the gut microbiota of sika deer (Cervus nippon). Twenty-four male sika deer were randomly allocated to one of four experimental diets: a basal diet with no arginine (CON, 0 g/day) or arginine supplementation groups that received 1 (LArg), 2 (MArg), or 3 (HArg) g/day of rumen-protected arginine. After an 8-week feeding trial, plasma metabolite levels were measured, and the faecal bacterial community was examined based on 16S rRNA gene sequencing. The final weight (P = 0.04) and daily gain of velvet antler (P = 0.04) in the HArg group were higher than those in the CON group. The glucose (P = 0.01) and triglyceride concentrations (P < 0.01) in plasma increased linearly, whereas the ALT (P = 0.01) and AST (P < 0.01) concentrations decreased linearly with the increase of arginine supplementation. In addition, the phosphoserine (P = 0.01), citrulline (P = 0.02), cystathionine (P = 0.01), ammonia (P = 0.01), and arginine (P = 0.01) levels increased linearly with the increase of arginine supplementation. Prevotella spp. were the dominant bacteria in the faeces of sika deer among the four groups. Principal coordinates analysis results showed that the bacterial communities and predicted functions of the CON group were different from those of the LArg, MArg and HArg groups based on the Bray-Curtis dissimilarity matrix (P < 0.01), unweighted UniFrac distance (P < 0.01), and weighted UniFrac distance (P < 0.01). The Firmicutes-to-Bacteroidetes ratios were higher (P < 0.01) in the arginine supplementation groups than that in the CON group. The relative abundances of Bacteroides spp., Rikenellaceae RC9, Treponema 2, Turicibacter spp., Romboutsia spp., Alistipes spp., and Phascolarctobacterium spp. were increased with dietary arginine supplementation, whereas the abundance of Prevotella spp. was decreased. Comparison of potential functions also showed enrichment of the fructose and mannose metabolism, pyruvate metabolism, propionate metabolism, and butyrate metabolism pathways. These results suggested that supplemental rumen-protected arginine affected sika deer metabolism and the gut microbiota.

The Role of Serum Metabolomics in Distinguishing Chronic Rhinosinusitis With Nasal Polyp Phenotypes.

Background: Chronic rhinosinusitis with nasal polyps (CRSwNP) is a heterogeneous disease characterized by different clinical features and treatment responsiveness. This study aimed to compare the serum metabolomics profiles between eosinophilic CRSwNP (eCRSwNP) and non-eosinophilic CRSwNP (neCRSwNP) and healthy controls (HC) and explore objective biomarkers for distinguishing eCRSwNP before surgery.Methods: Serum samples were collected from 33 neCRSwNP patients, 37 eCRSwNP patients, and 29 HC. Serum metabolomics profiles were investigated by ultra-high-performance liquid chromatography–mass spectrometry.Results: The analysis results revealed that neCRSwNP, eCRSwNP, and HC exhibited distinctive metabolite signatures. In addition, eCRSwNP could be distinguished from neCRSwNP referring to their serum metabolic profiles, and the top ten different metabolites were citrulline, choline, linoleic acid, adenosine, glycocholic acid, L-serine, triethanolamine, 4-guanidinobutyric acid, methylmalonic acid, and L-methionine, which were related to several most important pathways including arginine and proline metabolism; glycine, serine, and threonine metabolism; linoleic acid metabolism; and purine metabolism. Among these distinctive metabolites, citrulline, linoleic acid, adenosine, and 4-guanidinobutyric acid showed good predictabilities, and the serum levels of citrulline, linoleic acid, and adenosine were significantly correlated with tissue eosinophil (T-EOS) percentage and T-EOS count.Conclusion: eCRSwNP patients exhibited discriminative serum metabolic signatures in comparison with neCRSwNP patients and HC. These results suggested that metabolomics profiles contributed to understanding the pathophysiological mechanisms of CRSwNP and distinguishing its phenotypes

The shifted balance of arginine metabolites in acute myocardial infarction patients and its clinical relevance

The arginine metabolism as a target for cardioprotection in patients with ST-segment elevation myocardial infarction (STEMI) remains insufficiently understood. Arginine, ornithine, citrulline, asymmetric dimethylarginine (ADMA) and proline plasma levels were measured using liquid chromatography and tandem mass spectrometry in 70 consecutive STEMI patients upon admission and at 6-month follow-up and were compared with left ventricular function, volumes, and infarct characteristics determined by cardiac magnetic resonance imaging, and with 5-year clinical outcomes. Baseline median concentration of arginine was higher by 49% (P = 0.002) when compared to 6-month measurements and was correlated with an ischemia risk area (R = 0.34, P = 0.004) and infarct size (R = 0.33, P = 0.006). Following ischemia median citrulline/arginine index decreased when compared with 6-month result (P = 0.002), while citrulline/ornithine and arginine/ADMA ratios maintained unchanged indicating a shift of arginine metabolism from nitric oxide synthase (NOS) towards arginase. The 6-month arginine concentration reached the area under the ROC curve of 0.67 (95% confidence interval 0.54–0.81) for prediction of death, myocardial infarction or heart failure hospitalization and its value of < 29 µM was associated with lower event free survival (P = 0.02). In STEMI patients, during ischemia conversion of elevated plasma arginine was shifted from NOS towards arginase. Decreased 6-month arginine concentrations were associated with worse long-term outcomes.

Plasma levels of amino acids and derivatives in retinopathy of prematurity.

Background: Retinopathy of prematurity (ROP) is a retinal disease that causes blindness in premature infants. This study aimed to reveal the changes in amino acids and derivatives in the plasma of ROP patients compared with premature infants without ROP.Methods: Metabolomics targeting amino acids and their derivatives was conducted to assess their plasma levels in ROP patients (n=58) and premature infants without ROP (n=25), and KEGG pathway analysis was used to identify the involved pathways.Results: Among the 31 assessed metabolites, the levels of 4 amino acids were significantly altered in the ROP group. Creatinine was downregulated in the plasma of the ROP patients, while the levels of citrulline, arginine, and aminoadipic acid were upregulated in the ROP group. Significant correlations were identified between the ROP stage and plasma levels of citrulline, creatinine, and aminoadipic acid. The involved pathways included biosynthesis of amino acids, arginine and proline metabolism, and arginine biosynthesis.Conclusion: The plasma levels of citrulline, creatinine, arginine, and aminoadipic acid were significantly changed in ROP patients. These metabolites could be considered potential biomarkers of ROP, and their related metabolic pathways might be involved in ROP pathogenesis.

EFFECT OF DOXORUBICIN-INDUCED OXIDATIVE STRESS ON CITRULLINE CONCENTRATION IN THE SMALL INTESTINAL MUCOSA AND PLASMA BLOOD IN RATS WITH NON-ALCOHOLIC STEATOHEPATITIS

The aim: Is to investigate the effect of doxorubicin-induced oxidative stress on plasma citrulline and citrulline concentration in the small intestinal (SI) mucosa of rats with non-alcoholic steatohepatitis (NASH). Materials and methods: The studies were carried out on 30 white non-linear adult rats, 15 (50%) males, 15 (50%) females, weighing 160-220 g. The rats were divided into three groups: І (n=10) – rats without NASH, received a standard diet, subsequently were injected with doxorubicin in cumulative dose of 15 mg/kg; ІI (n=10) – rats with NASH, received a high-calorie diet with doxorubicin injection similarly to group I; ІІІ (n=10) –control group, received a standard diet, were injected with placebo. In the SI mucosa, the levels of thiobarbituric acid reactive substances (TBARS), citrulline and catalase were determined. Also the level of plasma citrulline was analyzed. Results: Doxorubicin injection resulted in induction of oxidative stress in rats of group I and II, which was characterized by 2.1 (p=0.002) and 1.4 times (р=0.0059) increase in TBARS and in 3.4 (р=0.002), and 5.2 times (р=0.002) decrease in catalase activity respectively comparing with the control group. Simultaneously plasma citrulline level in group I and II was in 1.4 (р=0.0039) and 1,5 times (р=0.0039) respectively lower, compared to the control group. Conclusions: Doxorubicin-induced SI injury was associated with a significant decrease in plasma citrulline in rats regardless of NASH. The plasma citrulline could become an important marker in the assessment of the SI injury in clinical practice.

Low birth weight and lead exposure: An etiological approach

Low birth weight (LBW) is a worldwide public health problem as it is the most important cause of infant deaths and contributes significantly to the burden of childhood problems. There are many studies that have investigated the relationship between LBW and lead exposure, but the mechanism underlying lead exposure and increased risk of LBW are still unknown. In our study, we aimed to determine the effect of lead on endothelial dysfunction by investigating the relationship between the severity of exposure, birth weight and methylated arginines in pregnant women. The study was carried with 165 pregnant women. Placental methylated arginines (ADMA, SDMA, L-NMMA), arginine, citrulline, homoarginine cadmium and lead levels were analyzed. Pb level was significantly higher in the 25% and below percentile group compared with other groups. There was a negative correlation between birth weight and Pb levels. A statistically significant correlation was found between Pb and birth length, Cd, ADMA and SDMA. It is possible to say that the underlying mechanism in fetal growth retardation due to lead exposure can be linked to placental endothelial dysfunction.