Measurement of endogenous allantoin excretion in sheep urine

1982 ◽  
Vol 98 (1) ◽  
pp. 221-223 ◽  
Author(s):  
Anna M. Antoniewicz ◽  
P. M. Pisulewski
Keyword(s):  
Nucleic Acid ◽  
Rumen Microorganisms ◽  
Purine Base ◽  
Purine Bases ◽  
Tissue Turnover ◽  
Micro Organisms ◽  
Sheep Urine

Urinary allantoin, an end product of purine base metabolism, originates in sheep from three possible sources: exogenous, purine bases of rumen microorganisms and feed purines and ureides, and endogenous, purines catabolized in tissue turnover. Earlier studies suggested that nucleic acid purines of rumen micro-organisms may be a predominant source of urinary allantoin (Antoniewicz, Heinemann & Hanks, 1979, 1981).

The specificity of purine base and nucleoside uptake in promastigotes ofLeishmania braziliensis panamensis

Parasitology ◽  
1982 ◽  
Vol 85 (2) ◽  
pp. 271-282 ◽  
Author(s):  
B. D. Hansen ◽  
J. Perez-Arbelo ◽  
J. F. Walkony ◽  
L. D. Hendricks
Keyword(s):  
Competitive Interactions ◽  
Leishmania Braziliensis ◽  
Purine Base ◽  
Purine Bases ◽  
Uptake Rates ◽  
Nucleoside Uptake ◽  
And Diffusion

SUMMARYPromastigotes ofLeishmania braziliensis panamensisabsorbed the purines adenine, hypoxanthine, adenosine and inosine by a combination of diffusion and mediated components. When the uptake rates for these substrates were corrected for diffusion and compared, the purine bases adenine and hypoxanthine were transported at a significantly slower rate than the purine nucleosides adenosine and inosine. Competitive interactions among those purines tested confirmed the presence of mediated and diffusion components and suggested that three transport loci may be operating (Fig. 6). The first transport locus, designated Locus 1, transported inosine, Locus 2, the purine bases hypoxanthine and adenine and Locus 3, adenosine. In addition, adenine and hypoxanthine inhibited the uptake of one another competitively. A comparison of Kivalues derived from double reciprocal plots of labelled hypoxanthine and adenine uptake in the presence of the unlabelled substrates as inhibitors suggested that adenine has a greater affinity for the transport locus.

scholarly journals Recent developments in nucleic acid based techniques for use in rumen manipulation

2009 ◽  
Vol 38 (spe) ◽  
pp. 341-351 ◽  
Author(s):  
Christopher McSweeney ◽  
Seungha Kang ◽  
Emma Gagen ◽  
Carl Davis ◽  
Mark Morrison ◽  
...  
Keyword(s):  
Microbial Community ◽  
Nucleic Acid ◽  
Microbial Communities ◽  
Marker Gene ◽  
Molecular Ecology ◽  
Functional Gene ◽  
Rumen Microorganisms ◽  
Dna And Rna ◽  
Conventional Culture ◽  
Reference Strains

Nucleic acid-based techniques which can be used to characterise complex microbial communities without incubation are now being employed regularly in ruminant nutrition studies. Conventional culture-based methods for enumerating rumen microorganisms (bacteria, archaea, protozoa, and fungi) have been superseded and are now used mainly to obtain pure isolates of novel organisms and reference strains that are required for the development and validation of the nucleic acid approaches. These reference strains are also essential for physiological studies of the lifestyle of the organisms as well as sources of genomic DNA and RNA that can be analysed for functional gene activity. The foundation of the molecular ecology techniques is 16S/18S rDNA sequence analysis which has provided a phylogenetically based classification scheme for enumeration and identification of microbial community members. The use of this marker gene in assays involving the use of single nucleic acid probes or primer sets is rapidly evolving to high throughput approaches such as microarray analysis and new generation sequencing technologies. While these analyses are very informative for determining the composition of the microbial community and monitoring changes in population size, they can only infer function based on these observations. The focus of nucleic acid research is now shifting to the functional analysis of the ecosystem which involves the measurement of functional genes and their expression in the predominant or specific members of the rumen microbial community. Functional gene studies are less developed than 16S rDNA-based analysis of community structure. Also for gene expression studies there are inherent problems involved in extracting high quality RNA from digesta, and priming cDNA synthesis from bacterial mRNA. This paper reviews nucleic acid based molecular methods which have recently been developed for studying the structure and function of rumen microbial communities.

Nitrogen Excretion in Ascidiacea II. Storage Excretion and the Uricolytic Enzyme System

1965 ◽  
Vol 42 (2) ◽  
pp. 299-305
Author(s):  
IVAN GOODBODY
Keyword(s):  
Uric Acid ◽  
Calcium Carbonate ◽  
Protein Metabolism ◽  
Enzyme System ◽  
Purine Metabolism ◽  
Nitrogen Excretion ◽  
Purine Base ◽  
Purine Bases ◽  
Ascidiella Aspersa

1. The evidence for the occurrence of storage excretion in ascidians is reviewed. Most species probably store uric acid or purine bases in some form. 2. The renal concretions of Ascidia nigra and Phallusia mammillata contain 50-60% uric acid, the remainder of the concretion is unidentified but is non-nitrogenous and is not calcium carbonate. In Ascidiella aspersa the concretion is predominantly composed of calcium carbonate and there is no significant quantity of uric acid or purine base. 3. Uric acid is also identified in Molgula manhattensis, Polycarpa obtecta, Pyura vittata and Herdmania momus. 4. Storage excretion probably results from a deficiency in the uricolytic enzyme system. It is concluded that while protein metabolism is ammonotelic, purine metabolism is uricotelic or xanthotelic.

scholarly journals The Purine Efflux Pump PbuE in Bacillus subtilis Modulates Expression of the PurR and G-Box (XptR) Regulons by Adjusting the Purine Base Pool Size

2005 ◽  
Vol 187 (2) ◽  
pp. 791-794 ◽  
Author(s):  
Per Nygaard ◽  
Hans H. Saxild
Keyword(s):  
Bacillus Subtilis ◽  
De Novo ◽  
Efflux Pump ◽  
Purine Base ◽  
Purine Bases ◽  
Purine Analogs ◽  
Expression Of Genes ◽  
Genes Encoding ◽  
Transcriptional Fusions

ABSTRACT In Bacillus subtilis, the expression of genes encoding enzymes and other proteins involved in purine de novo synthesis and salvage is affected by purine bases and phosphoribosylpyrophosphate (PRPP). The transcription of the genes belonging to the PurR regulon is negatively regulated by the PurR protein and PRPP. The expression of the genes belonging to the G-box (XptR) regulon, including the pbuE gene, is negatively regulated by a riboswitch-controlled transcription termination mechanism. The G-box regulon effector molecules are hypoxanthine and guanine. pbuE encodes a purine base efflux pump and is now recognized as belonging to a third purine regulon. The expression of the pbuE gene is positively regulated by a riboswitch that recognizes adenine. Here we show that the expression of pbuE′-lacZ transcriptional fusions are induced by adenine to the highest extent in mutants which do not express a functional PbuE pump. In a mutant defective in the metabolism of adenine, the ade apt mutant, we found a high intracellular level of adenine and constitutive high levels of PbuE. A growth test using a purine auxotroph provided further evidence for the role of PbuE in lowering the intracellular concentration of purine bases, including adenine. Purine analogs also affect the expression of pbuE, which might be of importance for the protection against toxic analogs. In a mutant that overexpresses PbuE, the expression of genes belonging to the PurR regulon was increased. Our findings provide further evidence for important functions of the PbuE protein, such as acting as a pump that lowers the purine base pool and affects the expression of the G-box and PurR regulons, including pbuE itself, and as a pump involved in protection against toxic purine base analogs.

scholarly journals Studies on Production of Nucleic Acid and its Related Compounds by Micro-organisms

1962 ◽  
Vol 26 (10) ◽  
pp. 648-654 ◽  
Author(s):  
Yujiro YAMADA ◽  
Kazumi EZAWA ◽  
Yoshihisa KOAZE ◽  
Takeshi HARA
Keyword(s):  
Nucleic Acid ◽  
Micro Organisms ◽  
Related Compounds

The Effect of Level of Available Carbohydrate, Offered as a Supplement to a Forage Based Diet, on Intake, Milk Yield and Milk Composition.

1993 ◽  
Vol 1993 ◽  
pp. 183-183
Author(s):  
Rosemary Mansbridge
Keyword(s):  
Energy Intake ◽  
Milk Yield ◽  
Crude Protein ◽  
Milk Composition ◽  
Energy Output ◽  
Available Nitrogen ◽  
Rumen Microorganisms ◽  
Available Energy ◽  
Low Efficiency ◽  
Micro Organisms

It has been reported (Castlejon and Leaver 1990, Hill and Leaver 1991) that when offered as the sole forage intakes of urea treated whole crop cereals (UWCC) were high. However energy output in milk and liveweight change was less than expected from calculations of energy intake.The level of crude protein (CP) in UWCC is high, typically in the range 200-300 g CP/kg DM. It has been suggested that a non-synchronous supply of available energy and rapidly available nitrogen to the rumen microorganisms was responsible for the low efficiency of utilization reported.The work described here was carried out to determine whether the utilization of diets containing UWCC could be improved by increasing the supply of readily available carbohydrates to the rumen micro-organisms.

Expression of the high-affinity purine nucleobase transporter in mutant mouse S49 cells does not require a functional wild-type nucleoside-nucleobase transporter

1987 ◽  
Vol 7 (1) ◽  
pp. 97-103
Author(s):  
B Ullman ◽  
J Patrick ◽  
K McCartan
Keyword(s):  
Genetic Locus ◽  
Nucleoside Transport ◽  
Recessive Trait ◽  
Wild Type ◽  
Purine Base ◽  
Purine Bases ◽  
High Affinity ◽  
Low Concentrations ◽  
Guanine And Adenine ◽  
Mutant Cells

A novel type of somatic mutation that causes the expression of a high-affinity purine base permease (B. Aronow, D. Toll, J. Patrick, P. Hollingsworth, K. McCartan, and B. Ullmann, Mol. Cell Biol. 6:2957-2962, 1986) has been inserted into nucleoside transport-deficient S49 cells. Two classes of mutants expressing this nucleobase permease were generated. The first, as exemplified by the AE1HADPAB2 cell line, possessed an augmented capacity to transport low concentrations of the three purine bases, hypoxanthine, guanine, and adenine. The second class of mutants, as typified by the AE1HADPAB5 clone, possessed an augmented capability to translocate low levels of hypoxanthine and guanine, but not adenine. Neither the AE1HADPAB2 nor the AE1HADPAB5 cells could transport nucleosides, suggesting that the expression of the high-affinity base transporter did not reverse the mutation in the nucleoside transport system. The transport of purine bases by both AE1HADPAB2 and AE1HADPAB5 cells was much less sensitive than that by wild-type cells to inhibition by dipyridamole, 4-nitrobenzylthionosine, and N-ethylmaleimide, potent inhibitors of nucleoside and nucleobase transport in wild-type S49 cells. Fusion of the AE1HADPAB2 and AE1HADPAB5 cell lines with wild-type cells indicated that the expression of the high-affinity base transporter behaved in a dominant fashion, while the nucleoside transport deficiency was a recessive trait. These data suggest that the high-affinity purine base transporter of mutant cells and the nucleoside transport function of wild-type cells are products of different genes and that expression of the former probably requires the unmasking or alteration of a specific genetic locus that is silent or different in wild-type cells.

Studies on Production of Nucleic Acid and its Related Compounds by Micro-organisms

1962 ◽  
Vol 26 (10) ◽  
pp. 648-659
Author(s):  
Michio Kojima ◽  
Yoshihisa Koaze ◽  
Takeshi Hara
Keyword(s):  
Nucleic Acid ◽  
Micro Organisms ◽  
Related Compounds
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