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1

Przemiany energetyczne i metabolizm nukleotydow w sercu i ich znaczenie w kardiologii i kardiochirurgii

100%
Smolenski R. T.
Kosmos
|
1997
|
tom 46
|
nr 1
5-16
2

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

100%
Smolenski R. T.
Acta Biochimica Polonica
|
2000
|
tom 47
|
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
3

Degradation of adenine nucleotidcs in the erythrocytes of patients with chronic renal failure

63%
Smolenski R. T., Marlewski M.
Acta Biochimica Polonica
|
1990
|
tom 37
|
nr 1
4

Rola nukleotydów i sygnalizacji purynergicznej w stenozie aortalnej i miażdżycy tętnic

63%
Kutryb-Zajac B., Smolenski R. T.
Postępy Biologii Komórki
|
2017
|
tom 44
|
nr 1
5

Deaminacja adeniny i adenozyny u gronkowcow

51%
Krasuski A., Galinski J., Smolenski R. T., Marlewski M.
Medycyna Doświadczalna i Mikrobiologia
|
1997
|
tom 49
|
nr 3-4
113-122
Deaminations of adenine and adenosine by pattern strains of 24 staphylococcal species, were tested. During 3 hours of incubation of the suspensions of 8 staphylococci with adenine the liberation of ammonia occurred. The same staphylococci accumulated ammonia in the incubation medium with adenosine. The Staphylococcus intermedius PCM 2405 strain as opposite to the Staphylococcia aureus 536 strain in the media with adenine or adenosine accumulated hypoxanthine or inosine, respectively and ammonia. These results indicated that adenine deaminase (adenase) and adenosine deaminase activities were associated with the cells of the Staphylococcus intermedius PCM 2405 strain. Staphylococci were heterogenous within three species groups with respect to adenine and adenosine deaminations. Adenine and adenosine deaminations were absent in staphylococci belonging to the Staphylococcus simulans species group.
6

The effects of galactosamine on UTP levels in the livers of young, adult and old rats

51%
Kmiec Z., Smolenski R. T., Zych M., Mysliwski A.
Acta Biochimica Polonica
|
2000
|
tom 47
|
nr 2
Galactosamine (GalN), a well-known hepatotoxin that depletes the cellular pool of uracil nucleotides, was previously shown to have greater impact on the inhibition of protein synthesis in hepatocytes of old rats as compared with young animals (Kmiec 1994, Ann. N.Y. Ac. Sci. 717, 216-225). In the present study we compared the effects of GalN on the nucleotide content (measured by ion-exchange HPLC) in the livers of young (4 months), adult (12 months), and old (24-26 months old) rats two hours after its intraperitoneal administration. UTP content of the livers of old control rats was significantly lower (by 28%) than that of young animals. GalN administration decreased the UTP content in the livers of young, adult and old rats by, respectively, 55%, 65% and 89%, and increased the content of UDP-sugars by 189%, 175% and 305%. The hepatic content of ATP, ADP, AMP, NAD, GTP except CTP did not differ significantly among the age groups of rats studied, and was not changed by GalN treatment. The content of CTP was significantly higher in old rats (P < 0.03) upon GalN treatment. The lower hepatic content of UTP may partially explain the increased sensitivity of hepatocytes and livers of old rats to the action of galactosamine, and pos­sibly to other hepatotoxic compounds that decrease transcription in the liver.
7

Determination of nucleotides and its metabolic products in human saliva

51%
Kochanska B., Smolenski R. T., Knap N.
Cellular and Molecular Biology Letters
|
1999
|
tom 04
|
nr 3
8

Influence of heat stress on myocardial metabolism and functional recovery after cardioplegic arrest: A P N.M.R. study

51%
Jayakumar J., Smolenski R. T., Amrani M., Yacoub M. H.
Cellular and Molecular Biology Letters
|
1999
|
tom 04
|
nr 3
9

Determination of adenine nucleotides and their metabolites in human saliva

51%
Kochanska B., Smolenski R. T., Knap N.
Acta Biochimica Polonica
|
2000
|
tom 47
|
nr 3
The profile and normal concentrations of nucleotide metabolites in human saliva and reproducibility of these determinations were analyzed. Samples of human saliva collected from healthy individuals at weekly intervals, were deproteinized and analysed for the content of adenine nucleotides and their metabolites by reversed-phase HPLC. Initial ATP, hypoxanthine and uric acid concentrations were 0.52 0.15 µM, 1.91 0.37 µM and 184 22 µM respectively. A substantial individual variation persisted within 3 weeks of sampling excepted hypoxanthine which showed some unrelated variations. Determination of nucleotides and their catabolites in saliva due to its simplicity and reproducibility, may be of clinical value in diagnosis of local or systemic disorders.
10

The decrease in PPAR-alpha signalling in the failing human heart - a possible explanation for energy substrate preference switch

51%
Karbowska J., Kochan Z., Smolenski R. T.
Cellular and Molecular Biology Letters
|
2002
|
tom 07
|
nr Suppl.
11

Effect of heat stress on mitochondrial adenine nucleotide pools in rat myocardium

51%
Sammut I. A., Jayakumar J., Yacoub M. H., Smolenski R. T.
Cellular and Molecular Biology Letters
|
1999
|
tom 04
|
nr 3
12

Peroxisome proliferator-activated receptor alpha is downregulated in the failing human heart

51%
Karbowska J., Kochan Z., Smolenski R. T.
Cellular and Molecular Biology Letters
|
2003
|
tom 08
|
nr 1
Cardiac hypertrophy in humans is associated with a decrease in myocardial fatty acid β-oxidation (FAO) and accompanying alterations in metabolic gene expression. Flux through the cardiac FAO pathway, which is the principal source of energy production in the adult mammalian heart, is tightly controlled in accordance with energy demands. In rodents, the FAO pathway is under control of a nuclear peroxisome proliferator-activated receptor α (PPARα). We sought to delineate the molecular regulatory events involved in the energy substrate preference switch from fatty acids to glucose during cardiac hypertrophic growth in humans. We analysed the amount of PPARα protein in human cardiac tissue. PPARα protein level was measured in homogenates prepared from left ventricular biopsies taken from five control donor hearts and compared to the amount of this transcription factor in biopsies from five patients with compensated end-stage heart failure (HF) at the time of transplantation. Using Western blot analysis with a monoclonal antibody against human PPARα, we observed a significant decrease (54%) in the mean amount of PPARα in the group of HF patients compared to that in the donor tissue. This study indicates that the decrease in cardiac PPARα transcription factor gene expression observed in the failing human heart could play an important role in a reduction in fatty acid utilisation by the adult heart during cardiac hypertrophy.
13

Effects of heat stress on metabolism of high-energy phosphates: comparison of normothermic and hypothermic ischemia

51%
Jayakumar J., Smolenski R. T., Amrani M., Yacoub M. H.
Cellular and Molecular Biology Letters
|
1999
|
tom 04
|
nr 3
14

The effect of oxidative damage on ATP level in heat stressed endothelial cells

45%
Gray C. C., Smolenski R. T., Amrani M., Taylor G., Yacoub M. H.
Cellular and Molecular Biology Letters
|
1999
|
tom 04
|
nr 3
15

Ecto-5'-nucleotidase activity is reduced in the presence of TNF-alpha in human endothelial cells

45%
Kalsi K. K., Lawson C., McCormack A., Yacoub M. H., Smolenski R. T.
Cellular and Molecular Biology Letters
|
1999
|
tom 04
|
nr 3
16

Enhanced adenosine production in human endothelium by inhibition of adenosine metabolism and nucleotide precursor supply

39%
Smolenski R. T., Kalsi K. T., Gray C. C., Zych M., Kochan Z., Yacoub M. H.
Cellular and Molecular Biology Letters
|
1999
|
tom 04
|
nr 3
17

Changes of nucleotide content in human and rat heart during cardiac surgery and ischemia

39%
Smolenski R. T., Skladanowski A. C., Swierczynski J., Perko M., Narkiewicz M., Zydowo M. M.
Acta Biochimica Polonica
|
1993
|
tom 40
|
nr 4
The influence of ischemia on purine nucleotide and their catabolite concentration in human myocardium was investigated during surgery of acquired and congenital heart defects. This was compared with the influence of ischemia on rat heart. Concentrations of adenine and guanine nucleotides and their catabolites were measured in the extracts of heart biopsies taken at the onset of ischemia and at the time of reperfusion. The content of myocardial ATP in human heart decreased from the initial value of 223 ± 1.1 to 14.6 ±1.5 nmol/mg protein and total adenine nucleotide pool decreased from 34.2 ± 1.8 to 27.6 ± 1.5 nmol/mg protein during the operation. Significant increases in myocardial concentrations of purine catabolites were also observed with the most prominent rise in inosine from below 0.5 at the onset of the ischemia to 3.0 ± 0.5 nmol/mg protein at the time of reperfusion. A positive correlation was demonstrated between the concentration of purine catabolites in the heart at the end of ischemia with the decrease of both ATP and the total nucleotide pool. An interesting metabolic specificity of the ischemic human heart appeared to be only a small accumulation of inosine monophospahate (IMP). The increase of IMP in the rat heart after ischemia was several-fold higher.
18

Differences in adenine incorporation between human and rat heart endothelium

39%
Kalsi K. K., Zych M., Slominska E., Kochan Z., Yacoub M. H., Smolenski R. T.
Cellular and Molecular Biology Letters
|
1999
|
tom 04
|
nr 3
19

Energetics of cardiac myocyte in atherosclerosis

33%
Smolenski R. T., Toczek M., Bulinska A., Olkowicz M., Zabielska M., Pelikant-Malecka I., Kutryb-Zajac B., Slominska E. M.
Acta Biochimica Polonica
|
2018
|
tom 65
|
nr S2
20

Nucleotide and adenosine converting ecto-enzyme pattern in endothelial activation and vascular inflammation

33%
Kudryb-Zajac B., Mierzejewska P., Bulinska A., Jasztal A., Jablonska P., Serocki M., Bartoszewski R., Slominska E. M., Chlopicki S., Smolenski R. T.
Acta Biochimica Polonica
|
2018
|
tom 65
|
nr S2
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