Citrulline Levels Research Articles

Plasma citrulline, arginine, nitric oxide, and blood ammonia levels in neonatal calves with acute diarrhea.

BackgroundPlasma citrulline (CIT) concentration is considered to be a reliable marker of functional enterocyte mass, primarily in humans. However, information about CIT levels along with related metabolites, arginine (ARG), nitric oxide (NO), and ammonia in neonatal calves are lacking.ObjectivesTo compare plasma CIT, ARG, NO, and whole blood ammonia concentrations in neonatal calves with acute diarrhea with those in healthy calves and to assess their possible relationships with diarrhea‐related criteria.AnimalsSeventy neonatal calves (60 with acute diarrhea and 10 healthy).MethodsObservational case‐control study. Diarrheic calves were classified into subgroups on the basis of etiology, severity of diarrhea, degree of dehydration, and systemic inflammatory response syndrome (SIRS) status. Plasma CIT and ARG concentrations were measured by liquid chromatography/tandem mass spectrometry.ResultsPlasma CIT (median [range]: 67.5 [61.9‐75.4] vs 30.1 [15.0‐56.1] μmol/L) and ARG (170.7 [148.5‐219.5] vs 106.1 [54.4‐190.7] μmol/L) were lower and plasma NO (4.42 [3.29‐5.58] vs 6.78 [5.29‐8.92] μM) and blood ammonia concentrations (28.7 [26.1‐36.9] vs 59.8 [34.6‐99.5] μmol/L) were higher in the neonatal calves with diarrhea (P < .001). Plasma CIT (β = −0.29, P = .02), ARG (β = −0.33, P = .01), NO (β = 0.55, P < .001), and blood ammonia (β = 0.63, P <.001) were affected by SIRS status. Except for ammonia (0.52), the effects sizes for severity of diarrhea and degree of dehydration were small (ηp2 ≤ 0.45) for CIT, ARG, and NO.Conclusions and Clinical ImportanceThe changes in these variables might have diagnostic, prognostic, and therapeutic value in diarrheic neonatal calves.

Substantial Extracellular Metabolic Differences Found Between Phylogenetically Closely Related Probiotic and Pathogenic Strains of Escherichia coli.

Since its first isolation a century ago, the gut inhabitant Escherichia coli strain Nissle 1917 has been shown to have probiotic activities; however, it is yet not fully elucidated which differential factors play key roles in its beneficial interactions with the host. To date, no metabolomics studies have been reported investigating the potential role of small molecules in functional strain differentiation of Nissle from its genetically close neighbors. Here, we present results of liquid chromatography coupled to high-resolution mass spectrometry characterization of extracellular metabolomes of E. coli strains as a proxy of their bioactivity potential. We found that phylogroup B2 strains exported a more diverse arsenal of metabolites than strains of other phylogroups. Zooming into the phylogroup B2 metabolome identified consistent substantial differences between metabolic output of E. coli Nissle and other strains, particularly in metabolites associated to the Argimine biosynthesis pathway. Nissle was found to release higher levels of Ornithine and Citrulline whilst depleting greater amounts of Arginine from the medium. Moreover, a novel Nissle-specific metabolite not reported before in bacteria, 5-(Carbamoylamino)-2-hydroxypentanoic acid (Citrulline/Arginic Acid related) was observed. Finally, Nissle, CFT073 and NCTC12241/ATCC25922 shared the excretion of N5-Acetylornithine, whereas other strains released N2-Acetylornithine or no N-Acetylornithine at all. Thus, we found substantial metabolic differences in phylogenetically very similar E. coli strains, an observation which suggests that it is justified to further investigate roles of small molecules as potential modulators of the gut environment by probiotic, commensal, and pathogenic strains, including E. coli Nissle 1917.

Plasma Levels of Amino Acids Related to Urea Cycle and Risk of Type 2 Diabetes Mellitus in Chinese Adults.

Objective: This study aimed to test associations between type 2 diabetes mellitus (T2DM) and metabolites in urea cycle including arginine, citrulline and ornithine.Methods:This study used a hospital-based cross-sectional study design. We retrieved medical notes of 401 in-patients with onset of T2DM within 2 years and 1,522 healthy subjects who attended annual physical examination. All cases were admitted to a tertiary care center in Jinzhou, China from May 2015 to August 2016. Binary logistic regression analyses were performed to obtain odds ratios (ORs) and 95% confidence intervals (CIs).Results:Patients with T2DM had higher arginine, and lower ornithine than control subjects. Levels of citrulline were similar in two groups. Arginine was positively associated with T2DM (ORs: 1.20, 1.17–1.23) while ornithine was negatively associated with T2DM (OR: 0.89, 0.88–0.91). After adjustment for other amino acids and traditional risk factors, these associations were still significant and persistent for arginine and ornithine. The association between citrulline and T2DM was not significant. Their ratios of pairs of two amino acids were associated with increased risk of T2DM. After adjustment for other ratios of amino acids, effect size for T2DM remained significant. Further adjustment for traditional risk factors did not lead to large changes (ORs: 1.78, 1.20–2.65 for the ratio of arginine to ornithine; ORs: 1.59, 1.37–1.86 for the ratio of citrulline to ornithine, respectively) except the ratio of arginine to citrulline.Conclusions: Plasma levels of amino acids related to urea cycle and their ratios of these amino-acids were associated with T2DM in Chinese adults.

The Profile of Plasma Free Amino Acids in Type 2 Diabetes Mellitus with Insulin Resistance: Association with Microalbuminuria and Macroalbuminuria.

Altered plasma levels of branched-chain amino acids (BCAAs) and aromatic amino acids (AAAs) may predict the development of insulin resistance and other type 2 diabetes mellitus (T2DM) associated comorbidities. To elucidate the role of plasma free amino acids (PFAAs) profile as a biomarker for early detection of diabetic kidney disease, quantitative measurement of PFAAs profile was determined for 90 T2DM subjects, 30 were free of nephropathy, 30 with microalbuminuria, 30 with macroalbuminuria, and in addition to 30 healthy controls. The plasma levels of valine, leucine, isoleucine, phenylalanine, citrulline, and total BCAAs were significantly increased in diabetic normoalbuminuria group when compared to controls. However, the total BCAAs level was significantly decreased in diabetic patients with micro and macroalbuminuria. Other amino acid plasma levels as tyrosine, arginine, ornithine, glycine, and the total AAAs level were significantly decreased in all diabetic subgroups compared to controls. Significant positive correlations between total BCAAs, valine, leucine, isoleucine, serum insulin, glucose, and HOMA-IR values in the diabetic normoalbuminuria group were found. The use of altered PFAAs profile as a prognostic factor in T2DM patients at risk for microalbuminuria or macroalbuminuria might reduce or prevent the incidence of end-stage diabetic renal disease.

Identification of new biomarkers of bronchopulmonary dysplasia using metabolomics.

To identify new biomarkers of bronchopulmonary dysplasia (BPD) in preterm neonates. Metabolomic study of prospectively collected tracheal aspirate (TA) samples from preterm neonates admitted in 2 neonatal intensive care units measured by a mass spectroscopy-based assay and analysed using partial least squares-discriminant analysis. We evaluated 160 TA samples from 68 neonates, 44 with BPD and 24 without BPD in the first week of life. A cluster of 53 metabolites was identified as characteristic of BPD, with 18 select metabolites being highly significant in the separation of BPD versus No BPD. To control for the gestational age (GA) differences, we did a sub-group analyses, and noted that the amino acids histidine, glutamic acid, citrulline, glycine and isoleucine levels were higher in neonates with BPD. In addition, acylcarnitines C16-OH and C18:1-OH were also higher in neonates who developed BPD, but especially in the most preterm infants (neonates with GA < 27 weeks). Metabolomics is a promising approach to identify novel specific biomarkers for BPD.

Interplay of Nitric Oxide Synthase (NOS) and SrrAB in Modulation of Staphylococcus aureus Metabolism and Virulence.

Staphylococcus aureus nitric oxide synthase (saNOS) is a major contributor to virulence, stress resistance, and physiology, yet the specific mechanism(s) by which saNOS intersects with other known regulatory circuits is largely unknown. The SrrAB two-component system, which modulates gene expression in response to the reduced state of respiratory menaquinones, is a positive regulator of nos expression. Several SrrAB-regulated genes were also previously shown to be induced in an aerobically respiring nos mutant, suggesting a potential interplay between saNOS and SrrAB. Therefore, a combination of genetic, molecular, and physiological approaches was employed to characterize a nos srrAB mutant, which had significant reductions in the maximum specific growth rate and oxygen consumption when cultured under conditions promoting aerobic respiration. The nos srrAB mutant secreted elevated lactate levels, correlating with the increased transcription of lactate dehydrogenases. Expression of nitrate and nitrite reductase genes was also significantly enhanced in the nos srrAB double mutant, and its aerobic growth defect could be partially rescued with supplementation with nitrate, nitrite, or ammonia. Furthermore, elevated ornithine and citrulline levels and highly upregulated expression of arginine deiminase genes were observed in the double mutant. These data suggest that a dual deficiency in saNOS and SrrAB limits S. aureus to fermentative metabolism, with a reliance on nitrate assimilation and the urea cycle to help fuel energy production. The nos, srrAB, and nos srrAB mutants showed comparable defects in endothelial intracellular survival, whereas the srrAB and nos srrAB mutants were highly attenuated during murine sepsis, suggesting that SrrAB-mediated metabolic versatility is dominant in vivo.

Low CO2 induces urea cycle intermediate accumulation in Arabidopsis thaliana.

The non-proteinogenic amino acid ornithine links several stress response pathways. From a previous study we know that ornithine accumulates in response to low CO2. To investigate ornithine accumulation in plants, we shifted plants to either low CO2 or low light. Both conditions increased carbon limitation, but only low CO2 also increased the rate of photorespiration. Changes in metabolite profiles of light- and CO2-limited plants were quite similar. Several amino acids that are known markers of senescence accumulated strongly under both conditions. However, urea cycle intermediates respond differently between the two treatments. While the levels of both ornithine and citrulline were much higher in plants shifted to 100 ppm CO2 compared to those kept in 400 ppm CO2, their metabolite abundance did not significantly change in response to a light limitation. Furthermore, both ornithine and citrulline accumulation is independent from sugar starvation. Exogenous supplied sugar did not significantly change the accumulation of the two metabolites in low CO2-stressed plants, while the accumulation of other amino acids was reduced by about 50%. Gene expression measurements showed a reduction of the entire arginine biosynthetic pathway in response to low CO2. Genes in both proline biosynthesis and degradation were induced. Hence, proline did not accumulate in response to low CO2 like observed for many other stresses. We propose that excess of nitrogen re-fixed during photorespiration can be alternatively stored in ornithine and citrulline under low CO2 conditions. Furthermore, ornithine is converted to pyrroline-5-carboxylate by the action of δOAT.

Risk factors associated with mortality in neonatal intrahepatic cholestasis caused by citrin deficiency (NICCD) and clinical implications

BackgroundNeonatal intrahepatic cholestasis caused by citrin deficiency (NICCD) has high prevalence in East Asia, and has been reported in other parts of the world. NICCD is also the most common form of genetic cholestasis among East Asians. There has been reports of mortalities or liver transplants associated with NICCD, but risk factors associated with poor outcome were unknown. Our objective is to report NICCD mortalities in a tertiary pediatric hepatology center, and to explore associated risk factors along with implications to clinical practice.MethodThis is a retrospective analysis of NICCD cases collected from June 2003 until January 2017 in the Children’s Hospital of Fudan University. Clinical, biochemical, and genetic data were compared between deceased cases and survivors without liver transplant.ResultsSixty-one confirmed NICCD cases, including 52 cases in the survival group, and 9 cases in the mortality group, were included in the analysis. Mean age at referral in the mortality group was significantly higher when compared to the survival group (9.58 ± 5.03 VS 3.96 ± 3.13 months, p < 0.000). The proportion with infection in the mortality group was significantly higher than the survival group (p = 0.023). 44.4% of patients in the mortality group did not receive lactose-free and/or medium chain triglycerides enriched (LF/MCT) formula, and this percentage was significantly higher than the survival group (9.6%, p = 0.021). Mean platelet (PLT) count in the mortality group was significantly lower than the survival group (p = 0.010). Mean serum gamma-glutamyl transpeptidase (GGT), and total cholesterol (TCH) levels were significantly lower in the mortality group when compared to the survival group with p values of 0.001, and 0.019, respectively. Those who died had higher serum ammonium levels than survivors (p = 0.016). Mean level of citrulline was significantly lower in the mortality group compared to the survival group (p = 0.010). On the other hand, mean level of tyrosine was significantly higher in the mortality group than that of the survival group (p = 0.015).ConclusionLate referral, presence of infection, delayed treatment with LF/MCT formula, lower platelet count, lower levels of GGT, total cholesterol, blood citrulline, and higher level of blood ammonia and tyrosine, were associated with poor prognosis in NICCD.

Effect of a chamomile extract in protecting against radiation-induced intestinal mucositis.

Compounds that prevent radiation‐induced mucositis may offer new therapeutic strategies for maintaining intestinal integrity in patients undergoing radiotherapy. A specially formulated chamomile extract was studied with the hope of proving efficacy in this regard. Intestinal mucositis was induced in rats by exposing them to whole body gamma‐irradiation. Rats were treated orally with the extract for 5 days before and 2 days after radiation exposure. One day later, rats were sacrificed. Histological examination of segments of small intestine showed shortening and fusion of villi, activation of mucus secreting glands, inflammatory cell infiltration of lamina propria, and mucosal atrophy. Intestinal homogenates showed an increase in tumor necrosis factor, a pro‐inflammatory cytokine, and myeloperoxidase, an indicator of cellular infiltration, as well as in thiobarbituric acid reactive substances and a reduction in glutathione content. Intestinal injury was further evidenced by an increase in diamine oxidase and a reduction in citrulline levels in the serum. A rise in apoptosis was evidenced by an increase in cytosolic cytochrome c, caspase‐3, and depletion of mitochondrial B‐cell lymphoma‐2/ Bax ratio. Most histological changes and associated derangement in related parameters were largely prevented by the chamomile extract, thus paving the way to a new therapeutic approach towards the management of radiation‐induced intestinal mucositis.

Serum Citrulline Levels Exhibit Circadian Variation and Fluctuations in Relation to Food Intake in Mice.

BackgroundPlasma citrulline is a nonessential amino acid synthesized almost exclusively by enterocytes of the small intestine. Correlation between post-operative plasma citrulline levels and remnant small bowel mass and function has led to its use as a simple biomarker of functional intestinal mass in adults and children, with a proposed prognostic value for achieving enteral autonomy in the setting of intestinal failure. While it is standard to measure fasting levels in humans, the optimal timing of blood draws in relation to food intake and time of day has not been standardized and is poorly studied in animal models. We hypothesize that serum citrulline levels vary both throughout the day and with relation to food intake in mice.MethodsSerum citrulline levels were measured from 12 C57BL/6 mice (6 - 9 weeks old) in the mornings and evenings, either after ad libitum food intake or after 8 - 12 h of access to water only. Blood draws for each experimental set-up were performed 1 week apart according to our Institutional Animal Care and Use Committee (IACUC) guidelines for acceptable blood collection volumes for survival procedures. At the end of the experiment, mice were euthanized and small intestine was harvested for morphometric measurements. Group means were compared using Student’s t-test with significance assumed for P < 0.05.ResultsAfter withholding chow for 8 - 12 h, serum citrulline levels were significantly greater in the morning compared to levels drawn in the evening. When mice were allowed ad libitum chow, there was no significant difference in serum citrulline levels drawn in the morning compared to the evening. There was no difference detected in villus height across the different experimental conditions.ConclusionsSerum citrulline levels exhibit circadian variation and fluctuations in relation to food intake in mice, without apparent concurrent changes in enterocyte mass. There was no diurnal variation of serum citrulline levels in fed mice whereas fasted mice had significantly higher levels of serum citrulline in the morning compared to the evening. These findings underscore the paramount importance of consistent sample collection strategies in the setting of translational research.

The possibility of using citrulline as a new biochemical marker to evaluate the state of kidney under cardiovascular pathologies

The aim of our work was to study the level of citrulline in serum as a biochemical marker of the functional state of the kidneys in patients with cardiovascular pathologies.&#x0D; Methods. The study included 134 patients aged 41-68 years, of which 40 patients with stage II arterial hypertension (AG-II) and 62 patients with chronic heart failure (AG in combination with chronic ischemic heart disease) in the IIa and IIb stages. The control group included 32 practically healthy persons of the corresponding age. Along with standard diagnostic methods, the content of citrulline in serum was determined. Statistical analysis was performed using SPSS 10.0 for Windows.&#x0D; Results. There is a direct relationship between the increase in the content of citrulline and the severity of changes in the parameters of the functional state of the kidneys in patients with AG-II and CHF. At the same time, the fact that the content of citrulline in serum is much higher compared to the control values in patients with normal values of GFR, creatinine and microalbuminuria. As the increase in the content of citrulline directly correlates with the degree of deterioration of the functional state of the kidneys, and the kidneys are the only organ that regulates and controls the exchange of citrulline, the increase in its level in serum can be primarily associated with changes in kidney function in the examined patients.&#x0D; Conclusions. The content of citrulline in serum can be used as an additional marker for the presence of functional renal impairment in patients with cardiovascular and other diseases of the internal organs, especially in the early stages of development, as well as to assess the efficacy and safety of the use of drugs. This indicator needs further study involving more patients with different pathologies of the cardiovascular system and simultaneous monitoring of the functional status of the kidneys by standardized methods.

Clinical characterіstics and survival of hospitalized patients with chronic heart failure and reduced left ventricular ejection fraction depending on dynamics of nitrogen-releasing kidney function during period of overcoming clinical decompensation

The aim — to investigate the main clinical hemodynamic and laboratory characteristics in hospitalized patients with chronic heart failure (CHF), depending on the dynamics of the nitrogen‑releasing renal function during the period of overcoming decompensation and to determine the prognostic value of impaired renal function (IRF) in this category of patients.Materials and methods. The study involved 134 patients with CHF caused by ischemic heart disease or dilated cardiomyopathy, and a reduced (&lt; 40 %) left ventricular ejection fraction, heart failure of II B according to Strazhesko — Vasilenko criteria, III — IV functional class according to the criteria of the New York Heart Association (NYHA). They were hospitalized for circulatory decompensation. The median age was 59.5 (54; 68) years. All patients underwent general clinical examination, determined the level of creatinine, urea nitrogen, uric acid, interleukin‑6, plasma citrulline, N‑terminal fragment of the brain natriuretic peptide (NTproBNP) at admission and before discharge, glomerular filtration rate (GFR) using the equation CKD‑EPI. Patients received standard treatment. The patients were divided into two groups according to the level of increase in creatinine before discharge: the first one with RFW with an increase in creatinine level ≥ 17.7 mmol/l, the second one with no RFW.Results and discussion. 110 (82 %) patients showed no RFW after overcoming clinical decompensation; in 24 (18 %) patients, the creatinine level increased by 17.7 mmol/l or more, which corresponded to a decrease in GFR і 5 ml/(min 1.73 m2). At the stage of hospitalization, patients did not differ in age, frequency of comorbid pathology, main hemodynamic parameters, potassium plasma levels, glomerular filtration rate (GFR), urea nitrogen, uric acid, NTproBNP. After attaining the stable condition, lower blood pressure levels, higher levels of blood urea nitrogen, uric acid, interleukin‑6 and citrulline were observed in patients with impaired renal function. To overcome decompensation, these individuals took longer time, almost two times higher course and daily doses of loop and potassium‑preserving diuretics. Patients with impaired renal function had a statistically significantly worse prognosis regarding long‑term survival.Conclusions. Among patients with CHF and a reduced left ventricular ejection fraction (LVEF) hospitalized for circulatory decompensation, impaired renal function during treatment occurred in 18 % of cases. At the time of discharge, patients with impaired renal function compared with patients without one showed a significantly lower level of systolic blood pressure, a longer duration of decompensation overcoming, higher average daily doses of loop and potassium‑preserving diuretics, a higher content of uric acid, urea nitrogen, interleukin ‑6 and citrulline in plasma. Patients with decompensated CHF and impaired renal function had lower survival rate compared with patients without impaired renal function.

INFLUENCE OF CHRONIC NEUROGENIC PAIN ON DYNAMICS OF ENDOTHELIN-1 LEVEL AND COMPONENTS OF NO-SYSTEM DURING MELANOMA B16/F10 GROWTH

Chronic neurogenic pain is a pathogenic factor triggering mechanisms of homeostasis disfunction. As chronic neurogenic pain has been found to affect the biological features of B16/F10 melanoma, the purpose of the study was to determine the levels of endothelin-1 and components of the NO-system in mice during the growth of transplantable B16/F10 melanoma with chronic pain. Methods. The study included 64 female mice. B16/F10 melanoma was transplanted under the skin of the back to animals of the main group 2 weeks after the sciatic nerve ligation. Levels of endothelin-1, NOS-2, NOS-3, L-arginine, citrulline, total nitrite, nitrotyrosine and ADMA were determined by ELISA in the intact skin and in tumor tissues. Results. The dynamics of the studied parameters in tumor growth with and without chronic pain was different. Increased levels of endothelin-1 in the skin and in tumor tissues, stably elevated levels of NO-synthases in the tumor and stably elevated ADMA levels with their decrease by week 3 of the growth were observed in the tumor growth with pain. Conclusions. Chronic pain can contribute to the development of the immune tolerance to tumor antigens in the skin. Conditions are formed that both facilitate the survival of tumor cells and contribute to the further development of melanoma. The dynamics of activity of endothelin-1 and NO systems can promote stimulation of the epithelial-mesenchymal transition, enhance tumor invasion and hemangio- and lymphangiogenesis. Changes in the ADMA inhibitor levels in the tumor growth with chronic pain may indicate a more subtle control of the NO level providing increased melanoma invasiveness.

Clinical and instrumental characteristics of patients with chronic heart failure and reduced left ventricular ejection fraction without anemia, depending on the presence of iron deficiency

The aim – to compare patients with chronic heart failure (CHF) and reduced left ventricular ejection fraction (LVEF) without anemia depending on the presence of iron deficiency (ID) according to the main clinical, hemodynamic, laboratory parameters and prognosis indicators. Material and methods. In January – February, 2018, 95 stable patients with CHF (83 of men and 12 of women), 18–75 years old, NYHA class II–IV, with left ventricular ejection fraction &lt; 40 % were screened. Patients were included during clinical compensation phase. Quality of life was assessed by the Minnesota living with heart failure questionnaire (MLHFQ), physical activity was estimated by the Duke University index, functional status – by assessing the 6-minute walking test and a standardized lower limb extension test.Results. ID was found in 51 out of 95 patients without anemia. Patients with ID without anemia were reliably in higher functional class, had a lower body mass index, lower systolic blood pressure, glomerular filtration rate, worse 6-minute walking test and thigh quadriceps endurance and a lower quality of life by MLHFQ. They also had lower hemoglobin, MCV, MCH, hepcidin levels and higher NT-proBNP, interleukin 6, and citrulline levels. The presence of ID, even without concomitant anemia, increased both risk of death from any cause and the combined critical event risk (death or hospitalization) during 12 and 24 months.Conclusions. Among patients with CHF and reduced LVEF without anemia, ID was observed in 54 % of patients. Patients with ID were characterized by a greater proportion of patients in NYHA class III–IV and renal dysfunction, poorer functional capacity (6-minute walking test, thigh quadriceps endurance), poorer quality of life, lower body mass index, lower systolic blood pressure and lower hemoglobin and hepcidin levels along with higher circulating interleukin 6, citrulline and NT-proBNP levels. ID without concomitant anemia was associated with worse survival and more frequent hospitalizations.

Simultaneous analysis of acetylcarnitine, proline, hydroxyproline, citrulline, and arginine as potential plasma biomarkers to evaluate NSAIDs-induced gastric injury by liquid chromatography–tandem mass spectrometry

Although major adverse effects associated with nonsteroidal anti-inflammatory drugs (NSAIDs) are gastric injury, assessment of NSAIDs-induced gastrointestinal adverse effects is mostly dependent on endoscopy due to the lack of plasma biomarkers. Several amino acids associated with collagenase activity and gastric mucosal mass have been suggested as plasma biomarker candidates for gastric injury. Therefore, this study aimed to develop a liquid chromatography-tandem mass spectrometry (LC–MS/MS) method for the plasma biomarker candidates, i.e., acetylcarnitine, proline, hydroxyproline, citrulline, and arginine and evaluate their potential as a biomarker for NSAIDs-induced gastric injury. The method utilized simple protein precipitation with methanol and D4-citrulline as an internal standard (IS). The assay resulted in the lower limit of quantification (LLOQ) of 0.1 μg/mL for acetylcarnitine and 1 μg/mL for proline, hydroxyproline, citrulline, and arginine in the surrogate blank plasma. The intra- and inter-day accuracy ranged 82.5–111.2% for acetylcarnitine, 95.4–103.3% for proline, 98.9–106.4% for hydroxyproline, 99.5–103.5% for citrulline, and 87.4–105.3% for arginine. The precision was within 6.17%, 3.63%, 6.20%, 6.31%, and 6.17% for acetylcarnitine, proline, hydroxyproline, citrulline, and arginine, respectively. The developed assay was successfully applied to monitor the changes of the plasma levels of the five amino acids in rats and Beagle dogs following repeated oral administrations of aceclofenac. In rats, plasma concentrations of proline, hydroxyproline, and citrulline were significantly reduced after 4 days of aceclofenac administration compared to the control group. In dogs, plasma concentrations of proline and citrulline were significantly decreased after 7 days of aceclofenac administration compared to those obtained after the first aceclofenac administration. These data indicate that plasma levels of proline, hydroxyproline, and citrulline may be used as quantitative biomarkers of NSAIDs-induced gastric damage. The present assay could also be utilized to monitor the changes of these amino acids as potential indicators for various physiological and pathophysiological conditions.

Characterization of Arginine Catabolism by Lactic Acid Bacteria Isolated from Kimchi.

Kimchi fermentation depends on diverse lactic acid bacteria, which convert raw materials into numerous metabolites that contribute to the taste of food. Amino acids and saccharides are important primary metabolites. Arginine is nearly exhausted during kimchi fermentation, whereas the concentrations of other amino acids are reported not to increase or decrease dramatically. These phenomena could imply that arginine is an important nutritional component among the amino acids during kimchi fermentation. In this study, we investigated the arginine-catabolism pathway of seven lactic acid bacteria isolated from kimchi and evaluated the products of arginine catabolism (citrulline and ornithine) associated with the bacteria. The arginine content dramatically decreased in cultures of Lactobacillus brevis and Weissella confusa from 300 μg/mL of arginine to 0.14 ± 0.19 and 1.3 ± 0.01 μg/mL, respectively, after 6 h of cultivation. Citrulline and ornithine production by L. brevis and W. confusa showed a pattern that was consistent with arginine catabolism. Interestingly, Pediococcus pentosaceus, Lactobacillus plantarum, Leuconostoc mesenteroides, and Leuconostoc lactis did not show increased citrulline levels after arginine was added. The ornithine contents were higher in all bacteria except for L. lactis after adding arginine to the culture. These results were consistent with the absence of the arginine deiminase gene among the lactic acid bacteria. Arginine consumption and ornithine production were monitored and compared with lactic acid bacteria by metagenomics analysis, which showed that the increment of ornithine production correlated positively with lactic acid bacteria growth.

A Distinct Pattern of Circulating Amino Acids Characterizes Older Persons with Physical Frailty and Sarcopenia: Results from the BIOSPHERE Study.

Physical frailty and sarcopenia (PF&S) are hallmarks of aging that share a common pathogenic background. Perturbations in protein/amino acid metabolism may play a role in the development of PF&S. In this initial report, 68 community-dwellers aged 70 years and older, 38 with PF&S and 30 non-sarcopenic, non-frail controls (nonPF&S), were enrolled as part as the “BIOmarkers associated with Sarcopenia and Physical frailty in EldeRly pErsons” (BIOSPHERE) study. A panel of 37 serum amino acids and derivatives was assayed by UPLC-MS. Partial Least Squares–Discriminant Analysis (PLS-DA) was used to characterize the amino acid profile of PF&S. The optimal complexity of the PLS-DA model was found to be three latent variables. The proportion of correct classification was 76.6 ± 3.9% (75.1 ± 4.6% for enrollees with PF&S; 78.5 ± 6.0% for nonPF&S). Older adults with PF&S were characterized by higher levels of asparagine, aspartic acid, citrulline, ethanolamine, glutamic acid, sarcosine, and taurine. The profile of nonPF&S participants was defined by higher concentrations of α-aminobutyric acid and methionine. Distinct profiles of circulating amino acids and derivatives characterize older people with PF&S. The dissection of these patterns may provide novel insights into the role played by protein/amino acid perturbations in the disabling cascade and possible new targets for interventions.

Iron Deficiency Predictors in Patients with Chronic Heart Failure and Reduced Left Ventricular Ejection Fraction

The objective: to study the iron deficiency (ID) predictors in patients with chronic heart failure (CHF) and reduced left ventricular ejection fraction (rLVEF).Materials and methods. In a period from January 13, 2016 till February 28, 2018, on a basis of the Heart Failure Department of National Scientific Center «M.D. Strazhesko Institute of Cardiology, MAS of Ukraine» 134 stable patients with CHF (113 (84.3%) of men and 21 (15,7%) of women), 18–75 years old, NYHA class II-IV, with left ventricular ejection fraction &lt;40% were screened. Patients were included in a clinical compensation phase. Quality of life was assessed by the Minnesota living with heart failure questionnaire (MLHFQ), physical activity was estimated by the Duke University index, functional status – by assessing the 6-minute walking test (6MWT) and a standardized lower limb extension test.Results. ID was found in 83 (62%) of 134 patients with CHF and rLVEF. ID predictors are found to be the presence of anemia, III–IV NYHA functional class and the worse quality of life by the Minnesota questionnaire. There is a lower risk of developing ID in patients with NYHA class II and with greater thigh quadriceps endurance. Probability of ID decreases with higher values of hemoglobin, MCV, MCH, GFR. At the same time, higher levels of citrulline and NTproBNP are reliably associated with increased risk of ID occurrence. According to the results of multivariable regression model, independent ID predictors are decreased erythrocyte’s MCV and elevated NTproBNP level.Conclusions. Among patients with CHF and reduced LV EF, iron deficiency is found in 62% of cases and is dependent on concomitant anemia. Risk of ID is higher in patients with NYHA class III-IV, in patients with poorer quality of life, with elevated citrulline and NTproBNP levels. Hemoglobin, MCV, MCH, GFR and better thigh quadriceps endurance are directly associated with the presence of ID. Independent predictors of ID are MCV and NTproBNP levels.

The impact of sitagliptin, inhibitor of dipeptidyl peptidase-4 (DPP-4), on the ADMA-DDAH-NO pathway in ischemic and reperfused rat livers.

A correlation between the level of asymmetric dimethylarginine (ADMA) - the inhibitor of the nitric oxide (NO) synthesis - and the liver function and survival after a liver transplantation has been reported. The aim of this study was to evaluate the effect of sitagliptin -the inhibitor of dipeptidyl peptidase-4 (DPP-4) - on the NO-ADMA-dimethylarginine dimethylaminohydrolase (DDAH) pathway in rat livers subjected to ischemia/reperfusion (IR). The rats received sitagliptin (5 mg/kg, per os - p.o.) (groups: S - livers not subjected to IR procedure, and SIR - livers subjected to IR procedure) or a saline solution (groups: C - livers not subjected to IR procedure, and CIR - livers subjected to IR procedure) for 14 days; following this, livers in the SIR and CIR groups were subjected to ischemia (60 min) and reperfusion (24 h). Aminotransferases were measured before the surgery; additionally, the arginine (ARG), ADMA and symmetric dimethylarginine (SDMA) levels were estimated just before ischemia and during reperfusion (at 0.5, 4 and 24 h). After IR, citrulline, the DDAH activity, mRNA for type 1 DDAH (DDAH1), and arginine methyltransferase type 1 (PRMT1) were determined. The increase in the initial level of ARG/ADMA0 (A/A) ratio in group S compared to group C verged on statistical significance. At 0.5 and 4 h of reperfusion, the highest concentration of ADMA was found in group CIR. At those time points, the ARG level and the A/A ratio were decreased in groups CIR and SIR as compared to groups C and S, respectively. The alanine transaminase (ALT) activity was lower in the sitagliptin-treated group than in the non-treated one. The DDAH and citrulline levels were reduced in group CIR as compared to group C, but were greater in group SIR as compared to group S. The PRMT1 mRNA expression was higher in groups CIR and SIR, compared to groups C and S, respectively. The increased A/A ratio suggests a protective effect of sitagliptin on livers not subjected to IR. Changes in the DDAH activity and the PRMT1 mRNA expression also imply the protective activity of sitagliptin during IR.

Clinical and instrumental characteristics, clinical prognosis in patients with chronic heart failure and reduced left ventricular ejection fraction, depending on the presence and nature of the iron deficiency state

The aim – to compare patients with chronic heart failure and reduced left ventricular ejection fraction (LVEF) with absolute and functional iron deficiency (ID) state according to the main clinical, hemodynamic, laboratory parameters and clinical prognosis indicators. Material and methods. In January – February, 2018, 128 stable patients with chronic heart failure (111 of men and 17 of women), 18–75 years old, NYHA class II–IV, with left ventricular ejection fraction &lt; 40 % were screened. Patients were included in a clinical compensation phase. Quality of life was assessed by the Minnesota living with heart failure questionnaire (MLHFQ), physical activity was estimated by the Duke University index, functional status – by assessing the 6-minute walking test and a standardized lower limb extension test.Results. ID was observed in 61 % of patients, 65 % had absolute ID. Patients with both types of ID were in higher functional class, had a poorer quality of life and worse clinical and laboratory indices than patients without ID. Regardless of the difference in the functional and absolute ID formation mechanisms, no significant distinctions in the clinical and functional parameters, quality of life, as well as the parameters of intracardiac hemodynamics were found. Contrary to expectations, elevated levels of hepcidin were not detected in patients with functional ID compared to the absolute ID group. The reliable differences in survival/hospitalization rate between patients without ID and both groups of patients with ID allow us to recommend the screening of iron deficiency in all patients with chronic heart failure and reduced LVEF.Conclusions. ID is found in 61 % patients. Functional ID was found in 27 patients (21 %), absolute ID – in 51 patients (39.6 %). There were no differences between groups of patients with absolute and functional ID by age, functional class, LVEF, percentage of aneamic patients, 6-minute walking distance, thigh quadriceps endurance, quality of life, physical activity index, NT-proBNP, citrulline and hepcidin levels. Compared to patients with absolute ID, patients with functional ID had higher levels of hemoglobin, MCV, MCH, interleukin-6. Presence of both ID types was associated with worse survival and more frequent hospitalization.