Wyniki wyszukiwania

1

Elevation of the adenylate pool in rat cardiomyocytes by S-adenosyl-L-methionine

100%

Smolenski R. T.

Acta Biochimica Polonica

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2000

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tom 47

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nr 4

Rapid resynthesis of the adenylate pool in cardiac myocytes is important for recovery of contractility and normal function of regulatory mechanisms in the heart. Adenosine and adenine are thought to be the most effective substrates for nucleotide synthesis, but the possibility of using other compounds has been studied very little in cardiomyocytes. In the present study, the effect of S-adenosyl-L-methionine (SAM) on the adenylate pool of isolated cardiomyocytes was investigated and compared to the effect of adenine and adenosine. Adult rat cardiomyocytes were isolated using the collagenase perfusion technique. The cells were incubated in the presence of adenine derivatives for 90 min followed by nucleotide determination by HPLC. The concentrations of adenine nucleotides expressed in nmol/mg of cell protein were initially 22.1 ± 1.4, 4.0 ± 0.3 and 0.70 ± 0.08 for ATP, ADP and AMP, respectively (n = 10, ± S.E.M.), and the total adenylate pool was 26.8 ± 1.6. In the presence of 1.25 mM SAM in the medium, the adenylate pool increased by 5.2 ± 0.4 nmol/mg of cell protein, but only if 1 mM ribose was additionally present in the medium. No changes were observed with SAM alone. A similar increase (by 4.9 ± 0.6 nmol/mg protein) was observed after incubation with 1.25 mM adenine plus 1 mM ribose, but no increase was observed if ribose was omitted. Adenosine at 0.1 or 1.25 mM concentrations also caused an increase in the adenylate pool (by 5.2 ± 1.0 and 5.2 ± 0.9 nmol/mg protein, respectively), which in contrast to the SAM or adenine was independent of the additional presence of ribose. Thus, S-adenosyl-L-methionine could be used as a precursor of the adenylate pool in cardiomyocytes, which is as efficient in increasing the adenylate pool after 90 min of incubation as adenosine or adenine. Nucleotide synthesis from SAM involves the formation of adenine as an intermediate with its subsequent incorporation by adenine phosphoribosyltransferase

2

Nucleotide metabolism in an Italian APRT deficient patient

100%

Micheli V., Jacomelli G., Barberi S., Burroni B., Di Marcello F., Notarantonio L., Peruzzi L., Mazzaferro S., Pompucci G.

Cellular and Molecular Biology Letters

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1999

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tom 04

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nr 3

3

Pathways of purine metabolism: effects of exercise and training in competitive athletes

84%

Zielinski J., Kusy K.

Trends in Sport Sciences

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2015

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tom 22

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nr 3

Introduction. The main part of skeletal muscle adenosine- 5'-triphosphate (ATP) is restored by inosine monophosphate (IMP) reamination in the purine nucleotide cycle. The intramuscular resources of IMP may be resynthesized via the quick and economical salvage pathway, in which muscle hypoxanthine (Hx) is reconverted to IMP by hypoxanthineguanine phosphoribosyl transferase (HGPRT). IMP is subsequently reutilized in the adenine nucleotide (AdN) pool. Inosine and Hx, which flow out of the skeletal muscle, represent the loss of AdN precursors. In the latter case, full restoration of resting ATP levels depends on a slow and energy-consuming de novo pathway. Plasma Hx and erythrocyte HGPRT are indirect indicators of muscle metabolism, particularly of AdN degradation, that reflect exercise- and training-induced muscle energy status. Results. Our analyses of long-term training cycles in different sports show that plasma Hx concentration and erythrocyte HGPRT activity significantly change in consecutive training phases. Both high-intensity sprint training and endurance training incorporating high-intensity exercise lead to a decrease in plasma Hx levels and an increase in erythrocyte HGPRT activity. The lowest Hx concentration and the highest HGPRT activity are observed in the competition phase characterised by low-volume and high-intensity training loads. Training cessation in the transition phase brings about a reverse phenomenon: an increase in Hx levels and a decrease in HGPRT activity. Conclusions. Low plasma purine levels indicate that the administered training adapts the athletes to high-intensity exercise (more economical AdN use, limited purine efflux from muscle into the blood). Such an adaptation is of great importance for contemporary elite athletes. Purine metabolites are more sensitive markers of training status and better performance predictors than typical biochemical and physiological indicators (e.g. blood lactate and oxygen uptake) in highly-trained athletes of different specializations and ages. The use of Hx and HGPRT for monitoring and control of the training process is worthy of consideration.

4

Yeast: a eucaryotic model to study the genetic regulation of purine metabolism

84%

Lecoq K., Daignan-Fornier B.

Cellular and Molecular Biology Letters

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1999

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tom 04

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nr 3

5

Differences in adenine incorporation between human and rat heart endothelium

84%

Kalsi K. K., Zych M., Slominska E., Kochan Z., Yacoub M. H., Smolenski R. T.

Cellular and Molecular Biology Letters

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1999

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tom 04

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nr 3

6

Artykuł dostępny w postaci pełnego tekstu - kliknij by otworzyć plik

Microbiological and biochemical properties of soil depending on adenine and azotobacterin applied

84%

Wyszkowska J., Kucharski M., Kucharski J.

Journal of Elementology

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2008

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tom 13

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nr 1

The aim of the study was to determine how adenine affected biological proprieties of soil. The performance of this precursor cytokinine was tested in a pot trial. The question posed was whether it was possible to improve efficacy of adenine by enlarging populations of bacteria from Azotobacter species in soil. The experiment was carried out on proper brown soil, formed from dust clay sand with pHKCl 6,9. Pots were filled with 3.2 kg of soil. The investigations were performed in two series: with and without addition Azotobacterin to soil. Tow rates of nitrogen fertilisation: 0 and 50 mg N·kg-1 of soil were applied in test. Adenine was applied in the following quantities: 0; 5; 10 and 15 mg·kg-1 of soil. Radish, 6 plants per pot, was the test plant. It was confirmed that the adenine had a significant effect on growth and development of radish. It positively affected microbiological and the biochemical proprieties of soil. The counts of total oligotrophic bacteria, oligotrophic sporulation bacteria, total copiotrophic bacteria, copiotrophic sporulation bacteria, ammonifying bacteria, immobilizing bacteria, celulolytic bacteria, Azotobacter sp., Artrobacter sp. and Pseudomonas sp. were increased, and the number of fungi diminished. Adenine also stimulated activities of dehydrogenase, urease and alkaline phosphatase, although it depressed the activity of acid phosphatase. The inoculation with bacteria from Azotobacter species applied to soil failed to improve efficacy of adenine. Nevertheless, it increased counts of these bacteria, which had a beneficial influence on the development of oligotrophic bacteria, immobilizing bacteria, celulolytic bacteria and actinomyces, while negatively affecting fungi, ammonifying bacteria and Arthrobacter.

7

Micropropagation of Grewia tenax (Forssk.) Fiori – an important ethnomedicinal plant

67%

Daffalla H. M., Elsheikh A. M., Ali H. A., Khalafalla M. M.

BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology

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2019

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tom 100

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nr 3

8

Some kinetic studies on cytidine aminohydrolase activity from Aspergillus niger NRRL3

67%

Ali T. H.

Acta Microbiologica Polonica

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1998

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tom 47

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nr 4

9

Plasmalemma H - ATPase of plant and yeast origin

67%

Kotyk A.

Biophysics of Membrane Transport

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1992

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tom 11

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nr 1

10

DNA methyltransferases of Neisseria gonorrhoeae

67%

Piekarowicz A.

Acta Microbiologica Polonica

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1994

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tom 43

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nr 3-4

Ograniczanie wyników

Elevation of the adenylate pool in rat cardiomyocytes by S-adenosyl-L-methionine

Nucleotide metabolism in an Italian APRT deficient patient

Pathways of purine metabolism: effects of exercise and training in competitive athletes

Yeast: a eucaryotic model to study the genetic regulation of purine metabolism

Differences in adenine incorporation between human and rat heart endothelium

Microbiological and biochemical properties of soil depending on adenine and azotobacterin applied

Micropropagation of Grewia tenax (Forssk.) Fiori – an important ethnomedicinal plant

Some kinetic studies on cytidine aminohydrolase activity from Aspergillus niger NRRL3

Plasmalemma H - ATPase of plant and yeast origin

DNA methyltransferases of Neisseria gonorrhoeae