Uridine Monophosphate Research Articles

The results of a study on the safety of the dietary supplement neurouridine in patients with nonspecific low back pain (MULTINEURO-2)

To assess the efficacy and safety of high (300 mg) doses of the biologically active additive neurouridin (Unifarm) as part of complex therapy of patients with nonspecific low-back pain. Fifty patients (30 in the main group and 20 patients in the control group) were studied using a visual analogue scale (VAS), data from a general clinical analysis of blood and urine, a wide range of biochemical parameters, including liver function tests, glucose levels, creatinine, electrolyte levels. The positive effect of treatment with neurouridin on the dynamics of changes in pain according to the VAS was noted, a dose-dependent effect was revealed: patients at higher doses (300 mg of uridine monophosphate) showed a more significant regression of pain symptoms compared to standard doses. During the study, there were no serious adverse events allergic reactions. No clinically significant deviations of laboratory parameters were recorded.

Synthesis of α,δ-Disubstituted Tetraphosphates and Terminally-Functionalized Nucleoside Pentaphosphates.

The anion [P4O11]2-, employed as its bis(triphenylphosphine)iminium (PPN) salt, is shown herein to be a versatile reagent for nucleophile tetraphosphorylation. Treatment under anhydrous conditions with an alkylamine base and a nucleophile (HNuc1), such as an alcohol (neopentanol, cyclohexanol, 4-methylumbelliferone, and Boc-Tyr-OMe), an amine (propargylamine, diethylamine, morpholine, 3,5-dimethylaniline, and isopropylamine), dihydrogen phosphate, phenylphosphonate, azide ion, or methylidene triphenylphosphorane, results in nucleophile substituted tetrametaphosphates ([P4O11Nuc1]3-) as mixed PPN and alkylammonium salts in 59% to 99% yield. Treatment of the resulting functionalized tetrametaphosphates with a second nucleophile (HNuc2), such as hydroxide, a phenol (4-methylumbelliferone), an amine (propargylamine and ethanolamine), fluoride, or a nucleoside monophosphate (uridine monophosphate, deoxyadenosine monophosphate, and adenosine monophosphate), results in ring opening to linear tetraphosphates bearing one nucleophile on each end ([Nuc1(PO3)3PO2Nuc2]4-). When necessary, these linear tetraphosphates are purified by reverse phase or anion exchange HPLC, yielding triethylammonium or ammonium salts in 32% to 92% yield from [PPN]2[P4O11]. Phosphorylation of methylidene triphenylphosphorane as Nuc1 yields a new tetrametaphosphate-based ylide ([Ph3PCHP4O11]3-, 94% yield). Wittig olefination of 2',3'-O-isopropylidene-5'-deoxy-5'-uridylaldehyde using this ylide results in a 3'-deoxy-3',4'-didehydronucleotide derivative, isolated as the triethylammonium salt in 54% yield.

Use of SNPs from Illumina BovineSNP50K BeadChip v3 for imputation of microsatellite alleles for parentage verification and QTL reporting

The present study aimed to test the possibility of avoiding expensive retesting of the whole parental generation for single nucleotide polymorphisms (SNPs), to provide additional analysis of microsatellites in offspring in the transitional period and to analyse the likelihood of imputation of the International Society for Animal Genetics-recommended microsatellite markers from selected SNPs. The imputation and pedigree verification of 9 520 animals (representing 84 dairy bulls, 285 dairy cows, 3 202 beef bulls and 5 949 beef cows) were analysed by the method using 9 410 SNP haplotypes (incorporating an average of 73 SNPs per haplotype). The imputation method was confirmed to allow the parentage verification of up to 87% of the analysed animals without the need for retesting. The most problematic locus was TGLA53, with only 78% successful imputation. Seven loci (BM2113, ETH225, TGLA227, BM1824, SPS115, TGLA122 and TGLA126) had more than 90% imputing accuracy and success of imputation. The success of imputation also depends on the breed and the call rate of the test results. The highest imputation accuracy was found for the Holstein breed; the other six breeds had over 90% successful imputation rates, four breeds had imputation rates between 85.0 and 89.9%, and ten breeds (rarely bred in the Czech Republic) had imputation rates below 85.0%. A call rate of SNP tests lower than 90% indicates problems with haplotype construction and thus deterioration in the success of imputation. The analysis of a possibility of using all possible information from Illumina BovineSNP50K BeadChip v3 showed 109 SNPs encoding 51 quantitative trait loci markers. Haplotypes were designed for interpretation of the most important markers for diseases, exterior and performance. The most important markers for Holstein breeders were chosen as kappa- (variants A, B and E) and beta-casein (variants A1, A2), Holstein haplotypes affecting fertility (HH1, HH3, and HH4) and loci causing genetic defects, bovine leukocyte adhesion deficiency and deficiency of uridine monophosphate synthetase. The results estimated from bovine bead chips corresponded to the expected distribution of the incidence of these traits in the population and were verified by PCR-RFLP tests.

Untargeted metabolomic investigate milk and ruminal fluid of Holstein cows supplemented with Perilla frutescens leaf

Milk compounds are important for human nutrient requirements and health. The ruminal metabolic profile is responsible for dietary nutrition and determines milk production. Perilla frutescens leaf (PFL) is a commonly used medicinal herb due to its bioactive metabolites. This study elucidated the effects of PFL on the metabolome of two biofluids (rumen fluid and milk) of 14 cows fed a basic total mixed ration diet (CON, n = 7) and supplemented with 300 g/d PFL per cow (PFL, n = 7) by ultra-performance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry. Milk PE-NMe (18:1(9Z)/18:1(9Z)) and DG (18:0/20:4(5Z,8Z,11Z,14Z)/0:0), oleanolic acid, and nucleotides were upregulated, and milk medium-chain fatty acids (2-hydroxycaprylic acid) were down-regulated in response to PFL. The supplementation of PFL increased the abundance of pyrimidine nucleotides both in rumen fluid and milk. The pathways of pyrimidine metabolism and biosynthesis of unsaturated fatty acids were enriched both in the rumen fluid and milk. We also found the milk 2-hydroxycaprylic acid was positively correlated with ruminal uridine 5-monophosphate, and was negatively correlated with ruminal deoxycytidine, and the milk thymidine was positively correlated with ruminal icosenoic acid. This study found that the supplementation of PFL could alter the ruminal metabolic profiles and milk synthesis through regulation of the pathways of pyrimidine metabolism and biosynthesis of unsaturated fatty acids. Our new findings provide comprehensive insights into the metabolomics profile of rumen fluid and milk, supporting the potential production of Perilla frutescens milk in dairy cows.

The Mystery of Sub-Picosecond Charge Transfer Following Irradiation of Hydrated Uridine Monophosphate

The Mystery of Sub-Picosecond Charge Transfer Following Irradiation of Hydrated Uridine Monophosphate

Dietary guanosine‐monophosphate improves growth performance, feed utilization and intestinal morphology of whiteleg shrimp ( Litopenaeus vannamei ) maintained on soybean meal‐based diets

The present study evaluated the effects of dietary supplementation of individual or a combination of nucleotides in soya bean meal‐based diet on growth, survival, apparent digestibility and intestinal condition of whiteleg shrimp, Litopenaeus vannamei. The experimental protocol comprised a control set, and four test diets that were separately supplemented with 0.1% inosine monophosphate (IMP, D + I), 0.1% guanosine monophosphate (GMP, D + G), 0.1% mixture of IMP and GMP (D + IG) and 0.1% mixture of IMP, GMP, cytidine monophosphate (CMP) and uridine monophosphate (UMP) (D + IGCU). Triplicate groups of the shrimp (initial body weight = 0.99 ± 0.01 g) were fed four times daily for 8 weeks. Results demonstrated that D + G significantly enhanced body weight gain and specific growth rate in the shrimp compared with control and other dietary treatments with the various combinations of nucleotides (p 0.05). Shrimp fed D + G showed significantly higher feed intake and apparent net protein utilization compared with D + IGCU and, control and D + IG (p < 0.05) respectively. Nucleotide supplementation did not significantly improve the crude protein and lipid digestibility coefficients. This was evident when the data on these parameters were compared with those of the control. Shrimp fed D + G showed significantly improved intestinal villus height and body crude protein content (p < 0.05). In conclusion, GMP supplementation in soya bean meal‐based diet enhanced the growth, feed intake, protein utilization and villus height of L. vannamei.

Mass transfer process and separation mechanism of four 5′-ribonucleotides on a strong acid cation exchange resin

5′-ribonucleotides including adenosine 5′-monophosphate (AMP), cytidine 5′-monophsphate (CMP), guanosine 5′-monophosphate (GMP) and uridine 5′-monophosphate (UMP) have been widely used in the food and pharmaceutical industries. This work focused on the assessment of mass transfer process and separation mechanism of four 5′-ribonucleotides and counter-ion Na+ on the strong cation exchange resin NH-1. The intraparticle diffusion was determined as the rate-limiting step for the mass transfer of AMP, CMP, GMP, and Na+ on the resin NH-1 through the Boyd model. Meanwhile, a homogeneous surface diffusion model (HSDM) combing ion exchange and physical adsorption was proposed and tested against adsorption kinetic data in the batch adsorption systems. The fixed-bed film-surface diffusion model based on the HSDM was then developed and successfully predicted the concentration profiles of 5′-ribonucleotides and the change of pH at the outlet of the fixed-bed in the dynamic adsorption and separation process. Finally, the separation mechanism of 5′-ribonucleotides was presented combining model prediction and experimental results. The separation of UMP, GMP and CMP were mainly based on their differences in isoelectric points, while that of AMP and CMP were lied with the discrepancy of their physical adsorption binding capacity with the resin NH-1.

Expanding the clinical and genetic spectrum of CAD deficiency: an epileptic encephalopathy treatable with uridine supplementation

PurposeBiallelic CAD variants underlie CAD deficiency (or early infantile epileptic encephalopathy-50, [EIEE-50]), an error of pyrimidine de novo biosynthesis amenable to treatment via the uridine salvage pathway. We further define the genotype and phenotype with a focus on treatment. MethodsRetrospective case series of 20 patients. ResultsOur study confirms CAD deficiency as a progressive EIEE with recurrent status epilepticus, loss of skills, and dyserythropoietic anemia. We further refine the phenotype by reporting a movement disorder as a frequent feature, and add that milder courses with isolated developmental delay/intellectual disability can occur as well as onset with neonatal seizures. With no biomarker available, the diagnosis relies on genetic testing and functional validation in patient-derived fibroblasts. Underlying pathogenic variants are often rated as variants of unknown significance, which could lead to underrecognition of this treatable disorder. Supplementation with uridine, uridine monophosphate, or uridine triacetate in ten patients was safe and led to significant clinical improvement in most patients. ConclusionWe advise a trial with uridine (monophosphate) in all patients with developmental delay/intellectual disability, epilepsy, and anemia; all patients with status epilepticus; and all patients with neonatal seizures until (genetically) proven otherwise or proven unsuccessful after 6 months. CAD deficiency might represent a condition for genetic newborn screening.

UHPLC-MS/MS-Based Nontargeted Metabolomics Analysis Reveals Biomarkers Related to the Freshness of Chilled Chicken.

To identify metabolic biomarkers related to the freshness of chilled chicken, ultra-high-performance liquid chromatography–mass spectrometry (UHPLC–MS/MS) was used to obtain profiles of the metabolites present in chilled chicken stored for different lengths of time. Random forest regression analysis and stepwise multiple linear regression were used to identify key metabolic biomarkers related to the freshness of chilled chicken. A total of 265 differential metabolites were identified during storage of chilled chicken. Of these various metabolites, 37 were selected as potential biomarkers by random forest regression analysis. Receiver operating characteristic (ROC) curve analysis indicated that the biomarkers identified using random forest regression analysis showed a strong correlation with the freshness of chilled chicken. Subsequently, stepwise multiple linear regression analysis based on the biomarkers identified by using random forest regression analysis identified indole-3-carboxaldehyde, uridine monophosphate, s-phenylmercapturic acid, gluconic acid, tyramine, and Serylphenylalanine as key metabolic biomarkers. In conclusion, our study characterized the metabolic profiles of chilled chicken stored for different lengths of time and identified six key metabolic biomarkers related to the freshness of chilled chicken. These findings can contribute to a better understanding of the changes in the metabolic profiles of chilled chicken during storage and provide a basis for the further development of novel detection methods for the freshness of chilled chicken.

The transcription factors aryl hydrocarbon receptor and MYC cooperate in the regulation of cellular metabolism

The transcription factor AHR (aryl hydrocarbon receptor) drives the expression of genes involved in detoxification pathways in cells exposed to pollutants and other small molecules. Moreover, AHR supports transcriptional programs that promote ribosome biogenesis and protein synthesis in cells stimulated to proliferate by the oncoprotein MYC. Thus, AHR is necessary for the proliferation of MYC-overexpressing cells. To define metabolic pathways in which AHR cooperates with MYC in supporting cell growth, here we used LC-MS-based metabolomics to examine the metabolome of MYC-expressing cells upon AHR knockdown. We found that AHR knockdown reduced lactate, S-lactoylglutathione, N-acetyl-l-alanine, 2-hydroxyglutarate, and UMP levels. Using our previously obtained RNA sequencing data, we found that AHR mediates the expression of the UMP-generating enzymes dihydroorotate dehydrogenase (quinone) (DHODH) and uridine monophosphate synthetase (UMPS), as well as lactate dehydrogenase A (LDHA), establishing a mechanism by which AHR regulates lactate and UMP production in MYC-overexpressing cells. AHR knockdown in glioblastoma cells also reduced the expression of LDHA (and lactate), DHODH, and UMPS but did not affect UMP levels, likely because of compensatory mechanisms in these cells. Our results indicate that AHR contributes to the regulation of metabolic pathways necessary for the proliferation of transformed cells.

Direct Determination of Pseudouridine in RNA by Mass Spectrometry Coupled with Stable Isotope Labeling.

Pseudouridine (Ψ) is the only "mass-silent" nucleoside produced by post-transcriptional RNA modification. We developed a mass spectrometry (MS)-based technique coupled with in vivo deuterium (D) labeling of uridines for direct determination of Ψs in cellular RNA and applied it to the comprehensive analysis of post-transcriptional modifications in human ribosomal RNAs. The method utilizes human TK6/mouse FM3A cells deficient in uridine monophosphate synthase using a CRISPR-Cas9 technique to turn off de novo uridine synthesis and fully labels uridines with D at uracil positions 5 and 6 by cultivating the cells in a medium containing uridine-5,6-D2. The pseudouridylation reaction in those cells results in the exchange of the D at the C5 of uracil with hydrogen from solvent, which produces a -1 Da mass shift, thus allowing MS-based determination of RNA Ψs. We present here the experimental details of this method and show that it allows the identification of all Ψs in human major nuclear and nucleolar RNAs, including several previously unknown Ψs. Because the method allows direct determination of Ψs at the femtomole level of RNA, it will serve as a useful tool for structure/function studies of a wide variety of noncoding RNAs.

Metabolic engineering generates a transgene-free safety switch for cell therapy.

Safeguard mechanisms can ameliorate the potential risks associated with cell therapies but currently rely on the introduction of transgenes. This limits their application owing to immunogenicity or transgene silencing. We aimed to create a control mechanism for human cells that is not mediated by a transgene. Using genome editing methods, we disrupt uridine monophosphate synthetase (UMPS) in the pyrimidine de novo synthesis pathway in cell lines, pluripotent cells and primary human T cells. We show that this makes proliferation dependent on external uridine and enables us to control cell growth by modulating the uridine supply, both in vitro and in vivo after transplantation in xenograft models. Additionally, disrupting this pathway creates resistance to 5-fluoroorotic acid, which enables positive selection of UMPS-knockout cells. We envision that this approach will add an additional level of safety to cell therapies and therefore enable the development of approaches with higher risks, especially those that are intended for limited treatment durations.

Using arterial\u2013venous analysis to characterize cancer metabolic consumption in patients

Understanding tumor metabolism holds the promise of new insights into cancer biology, diagnosis and treatment. To assess human cancer metabolism, here we report a method to collect intra-operative samples of blood from an artery directly upstream and a vein directly downstream of a brain tumor, as well as samples from dorsal pedal veins of the same patients. After performing targeted metabolomic analysis, we characterize the metabolites consumed and produced by gliomas in vivo by comparing the arterial supply and venous drainage. N-acetylornithine, D-glucose, putrescine, and L-acetylcarnitine are consumed in relatively large amounts by gliomas. Conversely, L-glutamine, agmatine, and uridine 5-monophosphate are produced in relatively large amounts by gliomas. Further we verify that D-2-hydroxyglutarate (D-2HG) is high in venous plasma from patients with isocitrate dehydrogenases1 (IDH1) mutations. Through these paired comparisons, we can exclude the interpatient variation that is present in plasma samples usually taken from the cubital vein.

Identification of potential inhibitors of SARS-COV-2 endoribonuclease (EndoU) from FDA approved drugs: a drug repurposing approach to find therapeutics for COVID-19

SARS-CoV-2 is causative agent of COVID-19, which is responsible for severe social and economic disruption globally. Lack of vaccine or antiviral drug with clinical efficacy suggested that drug repurposing approach may provide a quick therapeutic solution to COVID-19. Nonstructural protein-15 (NSP15) encodes for an uridylate-specific endoribonuclease (EndoU) enzyme, essential for virus life cycle and an attractive target for drug development. We have performed in silico based virtual screening of FDA approved compounds targeting EndoU in search of COVID-19 drugs from commercially available approved molecules. Two drugs Glisoxepide and Idarubicin used for treatment for diabetes and leukemia, respectively, were selected as stronger binder of EndoU. Both the drugs bound to the active site of the viral endonuclease by forming attractive intermolecular interactions with catalytically essential amino acid residues, His235, His250, and Lys290. Molecular dynamics simulation studies showed stable conformation dynamics upon drugs binding to endoU. The binding free energies for Glisoxepide and Idarubicin were calculated to be –141 ± 11 and –136 ± 16 kJ/mol, respectively. The IC50 were predicted to be 9.2 µM and 30 µM for Glisoxepide and Idarubicin, respectively. Comparative structural analysis showed the stronger binding of EndoU to Glisoxepide and Idarubicin than to uridine monophosphate (UMP). Surface area calculations showed buried are of 361.8Å2 by Glisoxepide which is almost double of the area occupied by UMP suggesting stronger binding of the drug than the ribonucleotide. However, further studies on these drugs for evaluation of their clinical efficacy and dose formulations may be required, which may provide a quick therapeutic option to treat COVID-19. Communicated by Ramaswamy H. Sarma

A doubly auxotrophic CHO-K1 cell line for the production of recombinant monoclonal antibodies.

Chinese hamster ovary (CHO) cells are the most widely used mammalian hosts for recombinant protein production due to their hardiness, ease of transfection, and production of glycan structures similar to those in natural human monoclonal antibodies. To enhance the usefulness of CHO-K1 cells we developed a new selection system based on double auxotrophy. We used CRISPR-Cas9 to knockout the genes that encode the bifunctional enzymes catalyzing the last two steps in the de novo synthesis of pyrimidines and purines (uridine monophosphate synthase and 5-aminoimidazole-4-carboxamide ribonucleotide formyltransferase/IMP cyclohydrolase [ATIC], respectively). Survival of these doubly auxotrophic cells depends on the provision of sources of purines and pyrimidines or on the transfection and integration of open reading frames encoding these two enzymes. We successfully used one such double auxotroph (UA10) to select for stable transfectants carrying (a) the recombinant tumor necrosis factor-α receptor fusion protein etanercept and (b) the heavy and light chains of the anti-Her2 monoclonal antibody trastuzumab. Transfectant clones produced these recombinant proteins in a stable manner and in substantial amounts. The availability of this double auxotroph provides a rapid and efficient selection method for the serial or simultaneous transfer of genes for multiple polypeptides of choice into CHO cells using readily available purine- and pyrimidine-free commercial media.

Effects of feed crops and boiling on chicken egg yolk and white determined by a metabolome analysis

Compositional analyses of eggs have primarily focused on nutritional components, including large molecules, such as proteins. However, few reports have investigated the effects of heating and hen feed crops on taste components, such as free amino acids and sugars. Herein, water-soluble metabolites in raw and boiled eggs produced from chickens raised with corn- or rice-fed were analyzed. Each egg was separated into yolk and white, and freeze-dried samples were analyzed by CE-MS and LC-MS. Abundant metabolites included amino acids in yolks and sugars in whites. Compared to corn-fed, rice-fed resulted in three times higher betaine and uridine monophosphate concentrations in yolks and whites, respectively. Boiled whites contained more than four times higher concentrations of amino acids and fructose than raw whites. Metabolites in yolks exhibited minimal changes after boiling. Our findings support the use of water-soluble metabolomics to evaluate the effects of heating and feed crops on taste components.

LncRNA SNORD3A specifically sensitizes breast cancer cells to 5-FU by sponging miR-185-5p to enhance UMPS expression

Breast cancer is the most common cancer type in women. Long non-coding RNAs (lncRNAs) have been reported as potential new diagnostic markers, prognostic factors, and therapeutic targets in cancer. However, the specific roles and mechanisms of lncRNAs in breast cancer remain to be elucidated. Here we demonstrated the downregulation of lncRNA SNORD3A in breast cancer cells and tissues and verified its non-protein-coding property. SNORD3A overexpression had no effect on cell proliferation but specifically sensitized breast cancer cells to 5-fluorouracil (5-FU) in vitro and in vivo. Mechanistically, SNORD3A exerts its effect via enhancing uridine monophosphate synthetase (UMPS) protein expression. SNORD3A acts as a competing endogenous RNA for miR-185-5p, leading to UMPS protein upregulation. miR-185-5p overexpression disrupted the effect of SNORD3A on chemosensitization to 5-FU in vitro and in vivo. Moreover, Meis1 overexpression transcriptionally promotes SNORD3A expression, and Meis1 is downregulated in breast cancer cells and tissues. In breast cancer tissues, SNORD3A level positively correlates with Meis1 and UMPS protein levels, whereas miR-185-5p level negatively correlates with UMPS protein level. High SNORD3A transcript and Meis1 and UMPS protein levels predicts a better outcome, but high miR-185-5p level predicts a worse outcome in breast cancer patients receiving 5-FU-based chemotherapy. Our findings indicate that Meis1-regulated SNORD3A specifically sensitizes breast cancer cells to 5-FU via enhancing UMPS expression. The SNORD3A–UMPS axis may serve as a potential biomarker and therapeutic target to improve the efficacy of 5-FU-based chemotherapy for breast cancer patients.

Change of Initial Yield of a Hydrated Electron with Uridine Monophosphate Concentration Is Related to the Excitation Photon Energy in Transient Absorption Spectroscopy.

The initial yield of a hydrated electron (eaq-) in a solution under laser pulse irradiation was investigated by pump-probe transient absorption spectroscopy. The initial quantum yield of eaq- varies with the concentration of uridine monophosphate (UMP). The variation of the concentration of eaq- is often used to study the prehydrated electron (epre-) and eaq- attachment to UMP. The results of 320 and 260 nm excitations were compared. It was found that with the increase of UMP concentration, the initial yield of eaq- increases at 320 nm excitation, but decreases at 260 nm excitation. The further analysis indicates that some of the epre- attachments to UMP before solvation at 260 nm excitation result in the decrease of the eaq- yield. In addition, the absorption of UMP to 260 nm also causes the decrease of the eaq- yield. After the excitation at 320 nm, the phosphate group of UMP can release electrons more easily than that of water molecules by two-photon absorption, and therefore the eaq- yield increases. With the increase of UMP concentration, the decay rate of eaq- increases because eaq- is captured by UMP. The change of excitation photon does not affect the reaction rate of eaq- attachment to UMP. The longer lifetime of eaq- obtained at 260 nm excitation than 320 nm excitation is induced by the larger eaq- escape probability at 260 nm excitation. Our results show that the femtosecond pulse pump-probe transient absorption spectroscopy method should be cautiously used because of its complexity in studying the epre- attachment to nucleotides in an aqueous solution.

Controlling Surface Oxygen Concentration of a Nanocarbon Film Electrode for Improvement of Target Analytes.

A nanocarbon film consisting of nanocrystallites with mixed sp2 and sp3 bonds formed by unbalanced magnetron sputtering, was studied with respect to changes in the characteristics caused by the surface oxygen concentration. An electrochemical pretreatment (ECP) was conducted to change the surface oxygen concentration of the nanocarbon film. X-ray photoelectron spectroscopy (XPS) measurements revealed that nanocarbon films with different amounts of surface oxygen could be prepared. In addition, we observed no significant increase of surface roughness (Ra) at the angstrom level after ECP, owing to a stable structure containing 40% of sp3 bonds. The electrode characteristics, including the potential window, and electrochemical properties for some redox species, such as Ru(NH3)63+/2+, Fe(CN)63-/4- and some biomolecules, were investigated. The anodic potential limit became wider and ΔEp of Fe(CN)63-/4- became smaller at the treated nanocarbon film electrode than those of the as-deposited nanocarbon film electrode. Based on these results, we realized to measure uridylic acid (UMP) and inosine triphosphate (ITP) with a high oxidation potential by direct oxidation, which was difficult to measure at the as-deposited nanocarbon film electrode.

Effects of dietary nucleotides on growth, survival and metabolic response in whiteleg shrimp, Litopenaeus vannamei against ammonia stress condition

This trial was conducted to evaluate the effects of nucleotides on growth of whiteleg shrimp, Litopenaeus vannamei, and the survival and metabolic responses to ammonia stress test. Experimental diets were as follows: low fish meal diet (LFMD), and four LFMD test diets, each supplemented with 0.1% guanosine monophosphate (GMP), 0.1% inosine monophosphate (IMP), 0.1% mixture of GMP and IMP and 0.1% mixture of GMP, IMP, uridine monophosphate (UMP) and cytidine monophosphate (CMP). The shrimp specimens (initial body weight: 0.99 ± 0.01 g) were randomly allocated into five groups and fed four times daily for 8-weeks. After the trial, final body weight was recorded and haemolymph was withdrawn for haematological analysis. The shrimp was then challenged with 70 mg/L ammonia (LC50) for 10 days. Survival and haemolymph of the shrimp were taken after exposure to ammonia. The highest growth performance was observed in the shrimp fed diet supplemented with GMP (p < .05), while survival was not influenced by the test diets in the feeding trial. In the ammonia challenge test, the highest survival was observed in the shrimp fed GMP supplemented diet compared to others. The plasma protein, glucose and cholesterol levels increased in all the treatments while triglycerides level decreased post challenge. Cortisol level recovered at day 10th after the challenge. Shrimps fed with nucleotides diets showed higher protein and glucose level compared to control groups post challenge. In general, nucleotides supplemented in the diet enhanced growth, improved stress resistance while modulating the haemolymph metabolites in L. vannamei under ammonia stress.