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PubMed2003

Allantoin, the oxidation product of uric acid is present in chicken and turkey plasma.

Urate oxidase is not present in birds yet allantoin, a product of this enzyme, has been measured in birds. Studies were designed to compare the concentrations of plasma purine derivatives in chickens and turkeys fed inosine-supplemented diets. The first study consisted of 12 male chicks that were fed diets supplemented with 0.6 mol inosine or hypoxanthine per kilogram diet from 3- to 6-week-old. Study 2 consisted of 12 turkey poults (toms) fed inosine-supplemented diets (0.7 mol/kg) from 6- to 8-week-old. Plasma allantoin and oxypurines concentrations were measured weekly using high performance liquid chromatography. Plasma uric acid (PUA) in chickens fed inosine-supplemented diets increased from 0.31 to 1.34 mM (P<0.05) at the end of week 2. In turkeys, those fed control diet had 0.17 mM PUA concentration compared to 0.3 mM in those fed the inosine diet at week 2 (P<0.05). Allantoin concentration increased in chickens from week 1 to 2 while a decrease was observed in turkeys (P<0.005) for both treatments. These data show that allantoin is present in turkey and chicken plasma. The presence of allantoin in avian plasma is consistent with uric acid acting as an antioxidant in these species.

Allantoin↗
PubMedDate not supplied

Evaluation of allantoin levels as a new marker of oxidative stress in Behçet's disease.

The increased production of reactive oxygen species (ROS) from activated neutrophils in Behçet's disease (BD) and recurrent aphthous stomatitis (RAS) may result in increased oxidative stress. Uric acid can react rapidly with neutrophil-derived ROS to form allantoin. The purpose of the study was to evaluate the serum levels of allantoin as a new marker of oxidative stress in BD compared with malondialdehyde (MDA) levels as a well-known marker. Blood samples were obtained from 23 BD patients, 22 RAS patients as positive controls, and 21 healthy controls. When compared to the healthy controls, we found higher allantoin and MDA levels in the BD patients and higher MDA levels in the RAS patients. Serum ascorbic acid levels in the BD patients were significantly lower than in the controls. Increased allantoin and MDA levels suggest the possible involvement of free radicals in BD. As allantoin is only a product of uric acid oxidation by reactive oxygen and nitrogen species, it may also be used as a marker of oxidative stress in BD.

Adolescent↗
PubMed1992

Endogenous allantoin excretion in response to changes in protein supply in sheep.

Endogenous allantoin derives from the breakdown of tissue nucleic acids. This study examined the effect of changes in protein supply on endogenous allantoin excretion by sheep. The animals were nourished by infusions of volatile fatty acids into the rumen and casein into the abomasum, thus avoiding ruminal microbial fermentation (i.e., no supply of exogenous nucleic acids). While a constant energy supply was maintained, the protein supply was altered in one of two ways: 1) changed from 0 to 3000 mg casein-N/kg metabolic weight (W0.75) per day in progressive steps; or 2) completely removed from an initial constant level [500 mg N/(kg W0.75.d)]. With the first alteration, endogenous allantoin excretion was not directly affected by the daily N input or N retention, but was linearly correlated with the cumulative N retention. With the second alteration, allantoin excretion increased (35-145%) on the first day after removal of the protein supply and then fell to a level equivalent to, or lower than, that before protein removal. The results suggest that the changes in endogenous allantoin excretion may reflect remodeling of the metabolic state of the animal during periods when protein supply fluctuates.

Allantoin↗
PubMed1987

Allantoin transport in Saccharomyces cerevisiae is regulated by two induction systems.

We show that the allantoin transport system of Saccharomyces cerevisiae responds to two induction systems, one mediated by allophanate or its analog oxalurate and the other mediated by allantoin or its analog hydantoin acetate. The effects of the two inducers were additive in strain M85. Like other allantoin pathway genes, oxalurate-mediated induction of allantoin transport required a functional DAL81 gene product. Hydantoin acetate-mediated induction of the system, on the other hand, occurred normally in dal81 mutants. This suggests that induction was not only mediated by two separate inducers, but also involved different regulatory proteins. Induction is probably a transcriptionally regulated process, because addition of hydantoin acetate or oxalurate to the culture medium increased the steady-state levels of mRNA encoded by a gene required for allantoin transport (DAL4).

Allantoin↗
PubMed1998

Estimation of the flow of microbial nitrogen to the duodenum using urinary uric acid or allantoin.

Data were collected from six experiments using duodenally cannulated Holstein dairy cows (88 combinations of cow and period) to evaluate the relationship between urinary purine metabolites and microbial N flow. Experiments evaluated the effects of dietary factors on microbial N production, which included 1) varying concentrations of ruminally degradable protein and nonstructural carbohydrates, 2) supplemental sources of protected amino acids, 3) grass silage treated with fibrolytic enzymes, 4) bacterial inoculation of corn silage, and 5) ruminal starch availability as affected by corn silages of varying maturity. The coefficient of determination for individual experiments that measured the relationship between microbial N flow and allantoin or uric acid excretion in urine ranged from 0.01 to 0.68 and 0.02 to 0.82, respectively. Across all experiments, the coefficients of determination between microbial N flow and allantoin or uric acid excretion in urine were r2 = 0.002 and 0.11, respectively. Removal of data from one experiment improved the overall coefficient of determination between microbial N flow and urinary uric acid to r2 = 0.32. Urinary allantoin excretion across experiments was negatively correlated with microbial N flow, but urinary allantoin excretion within experiments was positively correlated with microbial N flow. Uric acid excretion in urine was positively correlated with microbial N flow across and within experiments, except for one experiment. Our data demonstrate that uric acid excretion in urine can be used to predict microbial N production, except in early lactation, and that urinary allantoin excretion cannot be used to predict microbial N production accurately among cows at different stages of lactation.

Allantoin↗
PubMedDate not supplied

[Physical and chemical characterization of allantoin-beta-cyclodextrin inclusion complex].

Solubility and bioavailability of poorly water-soluble drugs have been improved by the preparation as cyclodextrin inclusion complexes. The aim of this study is to obtain and characterize the inclusion compound allantoin-beta-cyclodextrin. Allantoin is a vegetable drug, poorly water-soluble (1:300), isolated from roots of Symphytum off. The solid inclusion complex was prepared by mixing with a adequate quantity of water and drying at 50 degrees C to the constant weight. It was used a different proportions between allantoin and beta-cyclodextrin (1:4, 3:7). The inclusion complex was characterized with RMN and IR spectrum and compared with results obtained from beta-cyclodextrin and allantoin alone. The experimental results were demonstrated the inclusion of allantoin in the lipophilic cavity of beta-cyclodextrin without physico-chemical changes.

Allantoin↗
PubMed1992

The allantoin and uracil permease gene sequences of Saccharomyces cerevisiae are nearly identical.

We have determined the structure of the allantoin permease (DAL4) gene of Saccharomyces cerevisiae. The gene putatively encodes a hydrophobic protein with a M(r) of 71,755. It possesses the alternating hydrophobic-hydrophilic regions similar to those found in many other integral membrane proteins. The most striking feature of the allantoin permease component encoded by DAL4 is its striking similarity to the uracil permease component encoded by FUR4. Although data available indicate that these proteins do not share any overlap of function, their predicted protein sequences are 68% identical, 81% similar, and their DNA sequences are 70% identical. The upstream regulatory region of DAL4 contains all of the characterized cis-acting elements previously reported for inducible allantoin pathway genes: six sequences homologous to UASNTR, the element responsible for nitrogen catabolite repression-sensitive activation of allantoin pathway gene expression, and two sequences homologous to the cis-acting element responsible for inducer-responsiveness of the allantoin pathway genes, UIS. The finding of these homologous sequences predicted to exist on the basis of DAL4's expression characteristics, supports and strengthens the suggestion that these elements mediate the functions we have previously ascribed to them.

Amino Acid Sequence↗
PubMed1985

Identification of crystalline allantoin in the urine of African Cricetidae (Rodentia) and its role in their water economy.

All eleven cricetid species, examined in this investigation, produced an off-white crystalline precipitate in their urine when deprived of water, whereas not one murid examined did so. This crystalline compound was identified as allantoin, a common end product of purine catabolism. The quantity found in the solid precipitate alone accounted for 47% of the total nitrogen excreted and was approximately 14 times greater than the predicted quantity of allantoin from purine degradation. It appears that there is a shift in nitrogen excretion from urea to allantoin in the Cricetidae. Water-deprived cricetids had higher urine osmolalities, urea concentrations and lower daily percentage body water turnovers than the murids. This can be explained by the substantial water savings associated with excreting solid allantoin. The discrepancy in the mode of nitrogen excretion between the two families inhabiting the Namib Desert can be attributed to their different evolutionary histories, the Cricetidae being pre-adapted for survival in deserts.

Adaptation, Physiological↗
PubMed2000

Hypoxanthine, uric acid and allantoin as indicators of in vivo free radical reactions. Description of a HPLC method and human brain microdialysis data.

A practical one-step high performance liquid chromatography (HPLC) method was developed for the simultaneous determination of hypoxanthine, uric acid and allantoin in small (4 microL) microdialysis samples. The rationale for this work was the current interest in hypoxanthine as a marker for energy perturbation in hypoxia/ ischemia, in uric acid as an endogenous antioxidant, and in allantoin as a marker for in vivo formation of reactive oxygen species (ROS). The method is based on ion pairing reversed phase chromatography and UV detection. The coefficient of variance for within and between run imprecision was generally below 5%, somewhat higher for concentrations close to the detection limit (0.4-1.0 pmoles). Recoveries ranged from 89 to 102% and linearity was observed in the concentration range from 0.25 to 25.0 mmol/L. There was an excellent correlation between the present method and available reference methods. The method was applied to cerebral microdialysis samples from a patient with severe subarachnoid haemorrhage complicated by secondary ischemia leading to cerebral infarction. The secondary ischemia was associated with an increase of hypoxanthine followed by increasing allantoin and uric acid levels. We submit that this pattern of chemical changes indicates increased ROS formation produced by secondary ischemia. The HPLC method appears to be a useful tool for studying changes of hypoxanthine, uric acid and allantoin levels in microdialysis samples.

Allantoin↗
PubMed1993

Measurement of allantoin in urine and plasma by high-performance liquid chromatography with pre-column derivatization.

A method is reported for determination of allantoin in urine and plasma based on high-performance liquid chromatography (HPLC) and pre-column derivatization. In the derivatization procedure, allantoin is converted to glyoxylic acid which forms a hydrazone with 2,4-dinitrophenylhydrazine. The hydrazone appears as syn and anti isomers at a constant ratio. These derivatives are separated by HPLC using a reversed-phase C18 column from hydrazones of other keto acids possibly present in urine and plasma and then monitored at 360 nm. All components were completely resolved in 15 min. Both the reagents and derivatization products are stable. Recovery of allantoin added to urine and plasma was 95 +/- 3.7% (n = 45) and 100 +/- 7.5% (n = 64), respectively. The lowest allantoin concentration that gave a reproducible integration was 5 mumol/l. The between-assay and within-day coefficients of variation were 2.8 and 0.6%, respectively.

Allantoin↗
PubMed2004

Simultaneous determination of allantoin, choline and L-arginine in Rhizoma Dioscoreae by capillary electrophoresis.

A rapid, easy and reproducible capillary electrophoresis (CE) method for the simultaneous determination of allantoin, choline and arginine in Rhizoma Dioscoreae was developed first time. Under the optimum condition, the three analytes could be well separated within 5 min in a 70 cm (60 cm effective length) x 75 microm i.d. capillary. The relative standard deviations for both migration time and peak height were less than 3.20%. The linear response range was 5.0-150, 0.9-100 and 1.0-200 microg/ml for arginine, choline and allantoin, respectively. The detection limit of three components was 2.0, 0.4 and 0.5 microg/ml for arginine, choline and allantoin, respectively. Contents of arginine, choline and allantoin in the crude drug of Rhizoma Dioscoreae could be easily determined by the proposed method with satisfactory results.

Allantoin↗
PubMed2005

Quantification of urinary allantoin by capillary zone electrophoresis during recombinant urate oxydase (rasburicase) therapy.

OBJECTIVES: Rasburicase (Fasturtec) is used to prevent or treat hyperuricemia associated with chemotherapy. We developed a capillary zone electrophoresis method to measure urinary allantoin, the degradation product of uric acid by rasburicase. DESIGN AND METHODS: Electrophoresis was performed using a P/ACE 5500 system (Beckman) with a fused silica capillary tube and a UV-visible detector set at 214 nm. Urine samples from 10 patients with non-Hodgkin's lymphoma were analyzed to validate the technique. RESULTS: Using a sodium tetraborate running buffer, urinary allantoin was separated from related compounds and internal standard in less than 30 min. The method was linear up to 1.25 g/L (quantification limit: 30 mg/L); precision was below 10%. The total amount of allantoin excreted in patients treated by rasburicase ranged from 1.5 g to 7.9 g/4 days. CONCLUSION: This CZE assay is a simple, rapid and reproducible method to measure allantoin in urine. Different elimination profiles have been found in patients treated with rasburicase.

Allantoin↗
PubMed1998

Determination of allantoin in biofluids using micellar electrokinetic capillary chromatography.

A micellar electrokinetic chromatographic method is described for the determination and quantitation of allantoin, an end-product of purine metabolism in mammals that is applicable to biofluids of different mammal species and man. The method was optimised following a study on the effect of pH and sample preparation procedure. Final conditions were 30 mM sodium tetraborate, pH 9.5, 75 mM sodium dodecyl sulphate, 20 kV and 20 degrees C. Allantoin was well resolved from endogenous compounds and could be determined in horse, dog, mouse and rabbit urine. No allantoin could be found in man. No complicated sample treatment was necessary, thus the developed method was rapid (< 5 min), sensitive (5 microM) and simple. Results from this work will permit the determination of allantoin in man as a measure of free radical generation reactions as well as its presence in the plasma and other biofluids with modification of the sample preparation procedures.

Allantoin↗
PubMed1998

Determination of allantoin in bovine milk by high-performance liquid chromatography.

Determination of allantoin in bovine milk based on high-performance liquid chromatography (HPLC) is described. Following dilution and filtration, milk samples were analysed directly. Separation and quantification of allantoin was achieved using a Spherisorb 5 NH2 column (250 x 4.6 mm ID), acetonitrile-water (90:10, v/v) mobile phase at a flow-rate of 2.0 ml min(-1), temperature 20 degrees C and monitoring the effluent at 214 nm. Total analysis time was 10 min. Recovery of allantoin added to milk was 97 (+/-3.7, n = 30)%. Lowest detectable concentration was 1 micromol l(-1). Within-day and between-day variability were less than 3%. Advantages of improved retention and separation of allantoin, and less complicated sample preparation exist over current methods.

Allantoin↗
PubMed1987

Measurement of allantoin and uric acid in human body fluids. A potential index of free-radical reactions in vivo?

Free-radical attack upon uric acid generates allantoin [Ames, Cathcart, Schwiers & Hochstein (1981) Proc. Natl. Acad. Sci. U.S.A. 78, 6858-6862]. Methods are described for the accurate measurement of uric acid and allantoin in human body fluids. The concentrations of uric acid and allantoin in human serum and synovial fluid are reported. It is suggested that measurement of changes in allantoin concentration may be a useful index of free-radical reactions taking place in vivo.

Allantoin↗
PubMed1973

Induction of the allantoin degradative enzymes in Saccharomyces cerevisiae by the last intermediate of the pathway.

Saccharomyces cerevisiae can degrade allantoin in five steps to glyoxylate, ammonia, and "CO(2)." We previously demonstrated that synthesis of the urea carboxylase-allophanate hydrolase multienzyme complex is contingent upon the presence of allophanic acid, the product of the urea carboxylase reaction. Since these enzymes catalyze the last two reactions of allantoin degradation, experiments were performed to establish whether or not the presence of allophanic acid was required for synthesis of any other enzymes participating in this degradative pathway. The data presented here indicate that allophanic acid is required for synthesis of all enzymes participating in allantoin degradation. This conclusion is based upon the observation that: (i) wild-type strains produced a large amount of allantoinase upon addition of allantoin, allantoate, ureidoglycolate, or urea to the medium, (ii) no increase in activity was observed unless the added compound could be metabolized to allophanate, (iii) strains lacking allophanate hydrolase contained large amounts of allantoinase even in the absence of added urea, and (iv) the urea analogue, formamide, was capable of inducing allantoinase synthesis in wild-type strains but would not serve this function in a strain lacking urea carboxylase.

Allantoin↗
PubMed1974

Nitrogen repression of the allantoin degradative enzymes in Saccharomyces cerevisiae.

Saccharomyces cerevisiae can utilize allantoin as a sole nitrogen source by degrading it to ammonia, "CO(2)," and glyoxylate. We have previously shown that synthesis of the allantoin degradative enzymes is contingent upon the presence of allophanate, the last intermediate in the pathway. The reported repression of arginase by ammonia prompted us to ascertain whether or not the allantoin degradative system would respond in a similar manner. We observed that the differential rates of allantoinase and allophanate hydrolase synthesis were not decreased appreciably when comparing cultures grown on urea to those grown on urea plus ammonia. These experiments were also performed using the strain and conditions previously reported by Dubois, Grenson, and Wiame. We found allophanate hydrolase production to be twofold repressed by ammonia when that strain was grown on glucose-urea plus ammonia medium. If, however, serine or a number of other readily metabolized amino acids were provided in place of ammonia, production of the allantoin degradative enzymes was quickly (within 20 min) and severely repressed in both strains. We conclude that repression previously attributed to ammonia may result from its metabolism to amino acids and other metabolites.

Alanine↗
PubMed1999

Genetic analysis of a chromosomal region containing genes required for assimilation of allantoin nitrogen and linked glyoxylate metabolism in Escherichia coli.

Growth experiments with Escherichia coli have shown that this organism is able to use allantoin as a sole nitrogen source but not as a sole carbon source. Nitrogen assimilation from this compound was possible only under anaerobic conditions, in which all the enzyme activities involved in allantoin metabolism were detected. Of the nine genes encoding proteins required for allantoin degradation, only the one encoding glyoxylate carboligase (gcl), the first enzyme of the pathway leading to glycerate, had been identified and mapped at centisome 12 on the chromosome map. Phenotypic complementation of mutations in the other two genes of the glycerate pathway, encoding tartronic semialdehyde reductase (glxR) and glycerate kinase (glxK), allowed us to clone and map them closely linked to gcl. Complete sequencing of a 15.8-kb fragment encompassing these genes defined a regulon with 12 open reading frames (ORFs). Due to the high similarity of the products of two of these ORFs with yeast allantoinase and yeast allantoate amidohydrolase, a systematic analysis of the gene cluster was undertaken to identify genes involved in allantoin utilization. A BLASTP search predicted four of the genes that we sequenced to encode allantoinase (allB), allantoate amidohydrolase (allC), ureidoglycolate hydrolase (allA), and ureidoglycolate dehydrogenase (allD). The products of these genes were overexpressed and shown to have the predicted corresponding enzyme activities. Transcriptional fusions to lacZ permitted the identification of three functional promoters corresponding to three transcriptional units for the structural genes and another promoter for the regulatory gene allR. Deletion of this regulatory gene led to constitutive expression of the regulon, indicating a negatively acting function.

Allantoin↗