Allantoin Production Research Articles

Factors altering allantoin excretion by sheep and goats

We have studied the factors of variation of the urinary allantoin excretion with sheep billy goats and goats during digestibility trials. The urinary excretion of nitrogen allantoin (Nal) is highly correlated with the intake of digestible organic matter (DOM) and soluble nitrogen (Ns) for the sheeps billy goats and goats. By multiple regression we have estimated the daily endogenous excretion of Nal at 160 mg (goats) and 60 mg (sheeps and billy goats) respectively 8.5 and 2.6 mg/kg W0.75. The differences observed between sheeps and billy goats (Nal = 27.3 +/- 11.3 and 32.2 +/- 9.4 mg/kg W0.75) agree with the differences observed in the DOM and Ns intakes. The dairy goats eat more than the billy goats (69.5 against 52.0 DOM/kg W0.75 and 412 against 315 mg Ns/kg W0.75) but they excrete less Nal (36.3 mg against 42.3/kg W0.75). During the first two weeks of lactation the goats with negative N balance excrete more Nal than the goats with positive N balance (78 mg Nal against 57 mg/100 g DOM). Although large variations of DOM and Ns, the amount of Nal excreted before and after kidding doesn't vary. In these last conditions the general relation between Nal and intake of DOM and Ns no longer holds. Since the disponible energy (MOD) and soluble nitrogen intake supplies for the rumen microorganisms influence the amount of synthetised microbials protein (and so the amount of nucleic acids entering the duodenum) our regressions confirm the assumption that the excretion of Nal is related with the nucleic acids metabolism. However when Nal is utilised as an index of the nucleic acids catabolism, the factors that are able to create the variations either in the endogenous production of allantoin (uterine involution, bodily mobilisation, foetus growth, mammary gland development) or in the nucleic acids valorization must be taken into account.

Effect of oral administration of fructose on purine nucleotide metabolism in rats

1. 1. Oral administration of fructose (4 g/kg body wt) accelerated the production of uric acid and allantoin in rat liver. 2. 2. Changes in the concentrations of various metabolites in the liver after the administration of fructose suggested that this was due to the acceleration of AMP degradation induced by the rapid fall in adenylate energy charge resulted from rapid phosphorylation of fructose with ATP.

Purine catabolism in isolated rat hepatocytes. Influence of coformycin

1. The catabolism of purine nucleotides was investigated by both chemical and radiochemical methods in isolated rat hepatocytes, previously incubated with [(14)C]adenine. The production of allantoin reached 32+/-5nmol/min per g of cells (mean+/-s.e.m.) and as much as 30% of the radioactivity incorporated in the adenine nucleotides was lost after 1h. This rate of degradation is severalfold in excess over values previously reported to occur in the liver in vivo. An explanation for this enhancement of catabolism may be the decrease in the concentration of GTP. 2. In a high-speed supernatant of rat liver, adenosine deaminase was maximally inhibited by 0.1mum-coformycin. The activity of AMP deaminase, measured in the presence of its stimulator ATP in the same preparation, as well as the activity of the partially purified enzyme, measured after addition of its physiological inhibitors GTP and Pi, required 50mum-coformycin for maximal inhibition. 3. The production of allantoin by isolated hepatocytes was not influenced by the addition of 0.1mum-coformycin, but was decreased by concentrations of coformycin that were inhibitory for AMP deaminase. With 50mum-coformycin the production of allantoin was decreased by 85% and the formation of radioactive allantoin from [(14)C]adenine nucleotides was completely suppressed. 4. In the presence of 0.1mum-coformycin or in its absence, the addition of fructose (1mg/ml) to the incubation medium caused a rapid degradation of ATP, without equivalent increase in ADP and AMP, followed by transient increases in IMP and in the rate of production of allantoin; adenosine was not detectable. In the presence of 50mum-coformycin, the fructose-induced breakdown of ATP was not modified, but the depletion of the adenine nucleotide pool proceeded much more slowly and the rate of production of allantoin increased only slightly. No rise in IMP concentration could be detected, but AMP increased manyfold and reached values at which a participation of soluble 5'-nucleotidase in the catabolism of adenine nucleotides is most likely. 5. These results are in agreement with the hypothesis that the formation of allantoin is controlled by AMP deaminase. They constitute further evidence that 5'-nucleotidase is inactive on AMP, unless the concentration of this nucleotide rises to unphysiological values.

Purine catabolism in isolated hepatocytes: influence of coformycin.

The nucleoside antibiotic coformycin1, a potent inhibitor of adenosine deaminase, has also been shown to interact with purified muscle AMP deaminase2. in rat liver extracts, maximal inhibition of adenosine deaminase and of AMP deaminase was observed with 10-7M and 5 × 10-5M coformycin respectively. In isolated rat hepatocytes the basal production of allantoin (30–40 nmol/min/g of cells) was not influenced by the addition of 10-7M coformycin, whereas the metabolization of adenosine was strongly inhibited. In hepatocytes in which the adenine nucleotide pool had been prelabelled with 14C adenine, 5 × 10-5M coformycin caused a 85 % inhibition of the basal production of allantoin and a complete suppression of the incorporation of 14C in the end products of purine catabolism.

Probable site of allantoin formation in nodulating soybean plants

Nodulated soybean plants contain high concentration of allantoin in all parts. Excision of nodules from the roots brought about a marked decrease in allantoin. To examine the function of nodules in allantoin production, nodulated and nodule-detached soybeans were fed with 15NH 3 for 1 week. High abundance of 15N was found in the amino acid-N fraction of both plants. In the root and stem of the nodulated plants, ca 80% of the nitrogen in this fraction was derived from the NH 3 added in the medium. Excess 15N was detected also in allantoin-N fraction, but the 15N content was very low in contrast to that in amino acid-N fraction. The site involved in the allantoin formation and the possible significance of its synthesis are discussed in relation to symbiotic nitrogen fixation.

Renal excretion of allantoin in rats: a micropuncture and clearance study.

Free-flow micropuncture and clearance studies were performed to evaluate the transport of allantoin inthe rat kidney. Inn all studies [2-14C]uric acid and [methoxy-3H]inulin were administered. With a two-step column chromatographic technique, radiolabeled uric acid and allantoin were separated in plasma, urine, and tubular fluid, and the [2-14C]allantoin concentration was determined. Tubular fluid collections were obtained under hydropenic and control coneated animals in the control and volume-expanded states. Clearance data were obtained in oxonic acid-treated animals under the same experimental conditions. These studies indicate that allantoin is not bound to plasma protein and is, therefore, freely filterable. Neither net reabsorption nor net secretion of allantoin was evident along the length of the nephron. The bubular handling of allantoin was demonstrated to be dissociated from that of uric acid in all experimental states. No significant intrarenal production of allantoin from uric acid was observed.

Allantoin production and its utilization in relation to nodule formation in soybeans

Abstract A remarkable accumulation and utilization of allantoin are observed in soybean plant bearing modules (Glycine max variety A62-1). To study ita physiological role, changes in activities and distribution of the enzymes concerning the purine catabolism (i.e., xanthine oxidase, uricase, allantoinase and allantoicase) were measured during development. Uricase activity was found in the radicles in the early stage of seedling development, and no difference of the enzyme activity was detected between the radicles of the nodulating variety (A62-) and non-nodulating variety (A62-2). On maturation the activity disappeared rapidly in radicles and appeared in leaves, pods and nodules. The activity in nodules was much higher than that in the leaves and the pods throughout the culture period. Xanthine oxidase activity was found in the radicles and nodules. Allantoinase activity was present in all regions of both varieties, and the specific activity in the nodules Was 2-10 times that in other regions. Allantoica...

Uremic inhibition of purine uptake by rat hepatic slices.

Measurements were made of the production of allantoin by liver slices prepared either from bilaterally nephrectomized rats or from normal, control rats in flasks containing either a) no added substrate, b) hypoxanthine, or c) xanthine. Uremic liver slices showed a 72.3% inhibition of augmented allantoin production with hypoxanthine as substrate and a 68.3% inhibition with xanthine as substrate. Next, uremic rat serum was added to liver slices prepared from normal rats along with either a) no added substrate, b) hypoxanthine, or c) xanthine. Normal rat serum replaced uremic rat serum in control experiments. In these paired experiments, uremic serum exerted an inhibitory effect on allantoin production of 78.0% when hypoxanthine was the substrate and of 83.6% when xanthine was the substrate. Studies on possible underlying mechanisms showed that the observed uremic inhibition of allantoin production by hepatic slices, in the presence of substrate (e.g., hypoxanthine), represents a decreased production of uric acid, secondary to the decreased hepatic uptake of substrate.

Depletion of liver adenine nucleotides induced by d-fructose : Dose-dependence and specificity of the fructose effect

The effect of d-fructose on adenine nucleotide metabolism was studied in rats in vivo by analyzing liver metabolite levels after intravenous fructose injections, and in vitro by measuring allantoin production by the isolated perfused liver after the addition of fructose to the perfusion medium. Significant depression of liver ATP and inorganic phosphate levels was demonstrated after fructose administration. Minimum effective dose was 0.25 m-mole, and maximum depression was observed after 5 min. Analogous, but quantitatively less impressive alterations were produced by l-sorbose and d-sorbitol, whereas d-glucose, d-galactose, d-mannose, d-ribose and 2-deoxy- d-glucose were without effect. In the perfusion studies, marked increase in allantoin production was observed after the addition of d-fructose to the perfusion medium. The minimum effective dose was 0.25 m-mole, corresponding to a mean initial concentration of 4.5 mM in the medium. Allopurinol prevented both the basal allantoin production and the fructose-induced increase. d-galactose, d-ribose, d-sorbitol, sodium- dl-lactate or ethanol did not influence the basal rate of allantoin release. The loss of liver adenine nucleotides in the in vivo experiments was of a similar order of magnitude as the amount of allantoin produced in the perfusion experiments, when calculated per total liver after equal doses of fructose. Therefore, accelerated degradation of preformed purines, rather than increased de novo synthesis, appears to be the main mechanism of fructose-induced increase in uric acid and allantoin production.

Lethal Synthesis in Cynodon dactylon Growing in Southern Africa

Badenhuizen, N. P. (U. Toronto, Ont., Can.), and E. N. Lawson. Lethal synthesis in Cynodon dactylon growing in southern Africa. Amer. Jour. Bot. 49 (2) : 158–167. Illus. 1962.—Both cultivated and wild forms of Cynodon dactylon are characterized in southern Africa by the random production of chlorotic shoots. Some properties of these shoots were typical of chlorotic shoots in general: increase in water and soluble nitrogen content, and inhibition of protein synthesis, chloroplast development and catalase activity. Others, such as sterility and enhanced respiratory activity, were more characteristic of plants treated with streptomycin or amitrol. Allantoin could be demonstrated in the chlorotic shoots and was found to produce chlorosis after being applied to Cynodon plants. Additional characteristics included decreased total and “active” iron content, accompanied by an increase in citric acid. So far, the weight of evidence, including the ultrastructure of the plastids, is not in favor of a mutation, a virus, a fungus, or iron deficiency as the ultimate cause of chlorosis in Cynodon. There appears to be a tendency towards the production of allantoin which may be triggered off more frequently under certain conditions of environment, until a concentration is reached when it irreversibly inhibits stages in the development of the chloroplasts.

LETHAL SYNTHESIS IN CYNODON DACTYLON GROWING IN SOUTHERN AFRICA

Badenhuizen, N. P. (U. Toronto, Ont., Can.), and E. N. Lawson. Lethal synthesis in Cynodon dactylon growing in southern Africa. Amer. Jour. Bot. 49 (2) : 158–167. Illus. 1962.—Both cultivated and wild forms of Cynodon dactylon are characterized in southern Africa by the random production of chlorotic shoots. Some properties of these shoots were typical of chlorotic shoots in general: increase in water and soluble nitrogen content, and inhibition of protein synthesis, chloroplast development and catalase activity. Others, such as sterility and enhanced respiratory activity, were more characteristic of plants treated with streptomycin or amitrol. Allantoin could be demonstrated in the chlorotic shoots and was found to produce chlorosis after being applied to Cynodon plants. Additional characteristics included decreased total and “active” iron content, accompanied by an increase in citric acid. So far, the weight of evidence, including the ultrastructure of the plastids, is not in favor of a mutation, a virus, a fungus, or iron deficiency as the ultimate cause of chlorosis in Cynodon. There appears to be a tendency towards the production of allantoin which may be triggered off more frequently under certain conditions of environment, until a concentration is reached when it irreversibly inhibits stages in the development of the chloroplasts.