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Influence of mofebutazone in comparison to phenylbutazone on the adenosine triphosphate level of polymorphonuclear cells and their migration.

Two pyrazolon derivatives--mofebutazone (CAS 2210-63-1) and phenylbutazone (CAS 50-33-9)--were compared as to their effects on the adenosine triphosphate (ATP) level of polymorphonuclear cells (PMNs) and their response to the migration of these cells. In the range of 10(-8) to 10(-3) mol/l neither mofebutazone nor phenylbutazone significantly changed the ATP level of PMNs. Compared to the untreated PMNs only phenylbutazone reduced the migration of PMNs significantly (chemotactic index (CI) 0.46) at a concentration of 10(-3) mol/l. On the other hand with mofebutazone no statistically significant abnormality on PMN migration was found. Direct statistical comparisons of the migration between specific concentrations of the two pharmaceuticals did not indicate a different migration behavior even at 10(-3) mol/l. These results show that in contrast to the chemical and pharmacological differences of mofebutazone and phenylbutazone their effect on the ATP level and the migration of PMNs is comparable.

Adenosine Triphosphate↗

Changes in intracellular Mg adenosine triphosphate and ionized Mg2+ during blood storage: detection by 31P nuclear magnetic resonance spectroscopy.

31P nuclear magnetic resonance (NMR) spectroscopy was used to measure changes in intra-erythrocyte Mg adenosine triphosphate (MgATP) and free Mg2+ during blood storage at 4 degrees C in standard citrate preservation media. The extent of Mg2+ complexation of ATP and the concentration of free Mg2+ were measured from the Mg2+-dependent chemical shift differences, at 22 degrees C, between the P beta and P alpha resonances of intracellular ATP. This difference changed from 721.0 +/- 1.4 Hz (mean +/- SE) on the day of collection to 741.0 +/- 3.4 Hz after three to seven days and 774.0 +/- 2.8 Hz after 11 to 40 days storage in either acid-citrate-dextrose (ACD) or citrate-phosphate-dextrose-adenine (CPDA-1). Changes in intracellular pH, detected from shifts in the intracellular Pi resonance, averaged 0.27 units after 11 to 40 days of storage. These data indicate a sizable decrease in the extent of Mg2+ complexation of ATP, and a decrease by a factor of 2.6 in free Mg2+, during the shelf-life of blood stored in ACD or CPDA-1.

Adenosine Triphosphate↗

[The accuracy and reverse effects of thallium myocardial SPECT using adenosine triphosphate loading in the diagnosis of coronary artery disease: comparison with other loading methods semiquantitatively].

The adverse effects and diagnostic accuracy of thallium-201 myocardial SPECT after intravenous infusion of adenosine triphosphate (ATP) were studied and compared with SPECT examinations with other type of loading. The subjects of the study were 147 patients with or without coronary artery disease, who underwent some type of loading SPECT and coronary arteriography (CAG) within 30 days. Myocardial ischemia was evaluated qualitatively in SPECT and was compared with CAG for the diagnostic accuracy of coronary artery disease. The degree of myocardial uptake defect was also calculated semiquantitatively using visual scoring method and compared with coronary artery severity score. The adverse effects occurred in 46.7% of ATP loading SPECT which was more frequent than DIP loading SPECT, but all of them were transient and mild. As for the diagnostic ability, the ATP loading SPECT was as effective as other type of loading in qualitative interpretation, and the perfusion defect scores showed a good correlation with coronary artery stenosis grade. The myocardial SPECT using ATP is safe and useful for the diagnosis of coronary artery disease especially in patients who cannot exercise.

Adenosine Triphosphate↗

Adenosine triphosphate production rates, metabolic economy calculations, pH, phosphomonoesters, phosphodiesters, and force output during short-duration maximal isometric plantar flexion exercises and repeated maximal isometric plantar flexion exercises.

Measurements of adenosine triphosphate (ATP) production rates, metabolic economy, intracellular pH, phosphodiesters, and phosphomonoesters along with the force output were used to study 90-s maximum voluntary contractions and two new exercise protocols (20-10 and 30-16 exercises). The 20-10 exercise consisted of thirty-one 20-s maximal voluntary contractions separated by 10-s rest periods. The 30-16 exercise consisted of twenty 30-s maximal voluntary contractions separated by 16-s rest periods. There were no differences in ATP production rates, metabolic economy, intracellular pH, or force output between the 20-10 and 30-16 exercises. The 20-10 exercises accumulated more phosphomonoesters than the 30-16 exercises. These increases in phosphomonoesters may be attributed to increased accumulations of glucose-6-phosphate and/or inosine monophosphate. The increased perception of effort reported during and after the 20-10 exercises was not present during the 30-16 or 90-s exercises. This increased perception of effort may be related to increases in lactate, glucose-6-phosphate, inosine monophosphate, and/or NH3.

Adenosine Triphosphate↗

Alteration of glucose consumption and adenosine triphosphate content in bone tissue of rats with different ages: the stimulatory effect of zinc.

The alteration in bone metabolism at different ages was investigated by estimating glucose consumption and adenosine triphosphate (ATP) content in a culture system of bone tissue from 3- and 30-week-old rats. The femoral-diaphyseal tissue was removed and cultured for periods up to 48 h in Dulbecco's Modified Eagle Medium. Bone tissue was incubated at 37 degrees C in 5% CO2/95% air in a medium containing either vehicle and zinc sulfate (10(-6) - 10(-4) M). The medium glucose consumed by bone tissue clearly increased in a 48 h-culture in 3-week-old rats, while the increase in 30-week-old rats was slight. The presence of zinc sulfate (10(-6) and 10(-5) M) caused a significant increase in bone glucose consumption in 3- and 30-week-old rats. ATP content in cultured bone tissue from 30-week-old rats fairly fell in comparison with that from 3-week-old rats. Bone ATP contents in 3- and 30-week-old rats were significantly increased by the presence of zinc (10(-4) M). The present findings suggest that bone energy metabolism deteriorates with increasing age, and that zinc has a stimulatory effect in elderly rats.

Adenosine Triphosphate↗

Effect of doxazosin on stretch-activated adenosine triphosphate release in bladder urothelial cells from patients with benign prostatic hyperplasia.

OBJECTIVES: Recent data suggest that the bladder urothelium may have a sensory function by way of release of adenosine triphosphate (ATP) during stretch, which then acts as a sensory neurotransmitter. Because benign prostatic hyperplasia (BPH) can give rise to irritative (hypersensory) voiding patterns, we questioned whether the bladder urothelium from patients with BPH released more ATP during in vitro stretch and whether doxazosin, an alpha(1)-adrenoceptor blocker, affects this purinergic mechanism. METHODS: Bladder urothelial biopsies from patients with BPH (n = 4) and controls (n = 4) were cultured using established techniques. In vitro stretch was performed with a Flexcell 2000 device that uses vacuum to deform the cell growth surface to impart a stretch force. Doxazosin (5 microM and 20 microM) was added to cells, and supernatants were collected at various points for ATP assay. ATP was assayed using the luciferin-luciferase reaction. ATP data were normalized to the time 0 value and expressed as a percentage of the baseline value. RESULTS: After 96 hours of stretch, the BPH urothelial cells released significantly more ATP than did the control urothelial cells (62.6% +/- 11.2% versus 24.2% +/- 5.4%, P = 0.005) and nonstretched BPH urothelial cells (62.6% +/- 11.2% versus 15.1% +/- 5.1%, P = 0.004). The augmented release of ATP by stretched BPH bladder urothelial cells was completely blocked by treatment with 20 microM doxazosin. CONCLUSIONS: Irritative voiding secondary to BPH may arise from increased ATP release by bladder urothelium during stretch. Doxazosin inhibits ATP release by way of an unknown mechanism that may or may not involve the alpha1-adrenoreceptor. Treatment for hypersensory voiding symptoms secondary to BPH might also target the urothelial purinergic pathway.

Adenosine Triphosphate↗

Extracellular adenosine triphosphate affects neural cell adhesion molecule (NCAM)-mediated cell adhesion and neurite outgrowth.

The neural cell adhesion molecule (NCAM) plays an important role in synaptic plasticity in embryonic and adult brain. Recently, it has been demonstrated that NCAM is capable of binding and hydrolyzing extracellular ATP. The purpose of the present study was to evaluate the role of extracellular ATP in NCAM-mediated cellular adhesion and neurite outgrowth. We here show that extracellularly added adenosine triphosphate (ATP) and its structural analogues, adenosine-5'-O-(3-thiothiophosphate), beta, gamma-methylenadenosine-5'-triphosphate, beta, gamma-imidoadenosine-5-triphosphate, and UTP, in varying degrees inhibited aggregation of hippocampal neurons. Rat glial BT4Cn cells are unable to aggregate when grown on agar but acquire this capacity when transfected with NCAM. However, addition of extracellular ATP to NCAM-transfected BT4Cn cells inhibited aggregation. Furthermore, neurite outgrowth from hippocampal neurons in cultures allowing NCAM-homophilic interactions was inhibited by addition of extracellular nucleotides. These findings indicate that NCAM-mediated adhesion may be modulated by extracellular ATP. Moreover, extracellularly added ATP stimulated neurite outgrowth from hippocampal neurons under conditions non-permissive for NCAM-homophilic interactions, and neurite outgrowth stimulated by extracellular ATP could be inhibited by a synthetic peptide corresponding to the so-called cell adhesion molecule homology domain (CHD) of the fibroblast growth factor receptor (FGFR) and by FGFR antibodies binding to this domain. Antibodies against the fibronectin type-III homology modules of NCAM, in which a putative site for ATP binding and hydrolysis is located, also abolished the neurite outgrowth-promoting effect of ATP. The non-hydrolyzable analogues of ATP all strongly inhibited neurite outgrowth. Our results indicate that extracellular ATP may be involved in synaptic plasticity through a modulation of NCAM-mediated adhesion and neurite outgrowth.

Adenosine Diphosphate↗

Use of extractable adenosine triphosphate to estimate the viable cell mass in dental plaque samples obtained from monkeys.

The viable cell mass in plaque samples obtained from monkeys was estimated by determining the concentration of extractable adenosine triphosphate (ATP), and total cell mass was estimated by measuring the protein content. The results were expressed in terms of the specific ATP and protein contents of Streptococcus sanguis. The viable counts estimated by these techniques were comparable to or exceeded viable counts obtained by other investigators using conventional bacteriological methods.

Actinomyces↗

Changes in sodium, potassium, and adenosine triphosphate contents of red blood cells in sepsis and septic shock.

Sepsis and septic shock were induced in fifteen awake rabbits by the infusion of live Escherichia coli. Sodium K+, and adenosine triphosphate (ATP) concentrations in red blood cells (RBC) and plasma were measured during the control, septic, and septic shock periods. The significant elevations of Na+ content in RBC during sepsis appeared to be primarily a function of increased cell membrane permeability. The significantly decreased intracellular K+ concentrations, accompanying the high Na+ levels of RBC later in shock, were consistent with progressive failure of the energy-dependent transport mechanism (Na+-k+ pump). Hyponatremia and hyperkalemia were apparent in the late stages of sepsis, these alterations reached statistically significant levels in the shock period. The electrolyte derangements associated with sepsis and septic shock could not be related to energy depletion. The continuous significant accumulations of ATP, observed in RBC and plasma, were interpreted as a result of decreased energy utilization and attributed to the diminished active ion transport by the impaired Na+-K+ pump.

Adenosine Triphosphate↗

Effects of adenosine triphosphate on the cardiovascular response to tracheal intubation.

Laryngoscopy and tracheal intubation often cause hypertension and tachycardia, which may be exaggerated during rapid-sequence induction of anaesthesia. The efficacy of adenosine triphosphate (ATP) in attenuating this response was studied in patients receiving ATP 0.05 mg kg-1 or 0.1 mg kg-1 simultaneously with the start of laryngoscopy. These data were compared with those for a control group receiving saline. Each group consisted of 10 patients undergoing elective surgery. Anaesthesia was induced with thiopentone 5 mg kg-1 i.v. and tracheal intubation was facilitated with vecuronium 0.2 mg kg-1 i.v. During anaesthesia, ventilation was assisted or controlled with 1% enflurane and 50% nitrous oxide in oxygen. Patients receiving saline showed a significant increase in mean arterial pressure and rate-pressure product associated with tracheal intubation. These increase after tracheal intubation were reduced in ATP-treated patients compared with those of the control group (P less than 0.05). The data suggest that a bolus injection of ATP is a simple, practical and effective method for attenuating the hypertensive response to laryngoscopy and tracheal intubation.

Adenosine Triphosphate↗

Dendritic cells exposed to extracellular adenosine triphosphate acquire the migratory properties of mature cells and show a reduced capacity to attract type 1 T lymphocytes.

We previously reported that chronic stimulation with low, noncytotoxic doses of extracellular adenosine triphosphate (ATP) induced a distorted maturation of dendritic cells (DCs) and impaired their capacity to initiate T-helper (Th) 1 responses in vitro. Here, we examined the effects of ATP on chemokine-receptor expression and chemokine production by DCs. ATP strongly induced expression of CXC chemokine receptor 4 on both immature and lipopolysaccharide (LPS)-stimulated DCs and slightly up-regulated CC chemokine receptor (CCR) 7 on both DC types. In contrast, ATP reduced CCR5 expression on immature DCs. These effects were confirmed at both the messenger RNA and protein levels and were not produced by uridine triphosphate (UTP). Consistent with the changed receptor expression, ATP increased migration and intracellular calcium of immature and mature DCs to stromal-derived factor 1 (CXC ligand [CXCL] 12) and macrophage inflammatory protein [MIP] 3 beta (CC ligand [CCL] 19), whereas responses to MIP-1 beta (CCL4) were reduced. DCs are an important source of chemokines influencing recruitment of distinct T-lymphocyte subsets. ATP, but not UTP, significantly reduced LPS-induced production of interferon-inducible protein 10 (CXCL10) and regulated upon activation, normal T-cell expressed and secreted chemokine (CCL5); increased secretion of macrophage-derived chemokine (CCL22); and did not change production of thymus and activation-regulated chemokine (CCL17). Consistent with these findings, supernatants from ATP-treated mature DCs attracted Th1 and T-cytotoxic 1 cells less efficiently, whereas migration of Th2 and T cytotoxic 2 cells was not affected. Our data suggest that ATP provides a signal for enhanced lymph node localization of DCs but that it may, at the same time, diminish the capacity of DCs to amplify type 1 immune responses.

Adenosine Triphosphate↗

Synthesis of adenosine triphosphate by way of potassium-sensitive phosphoenzyme of sodium, potassium adenosine triphosphatase.

The sodium and potassium ion pump is an intrinsic enzyme of plasma membranes. In these experiments it was driven backward in a transient two-step operation involving, first, phosphorylation of the enzyme from inorganic phosphate, and second, transfer of the phosphate group from the enzyme to ADP upon addition of a high concentration of Na+. There was no evidence of a significant concentration gradient across the membranes. Na+ presumably reached the solutions on both faces of the membrane simultaneously and provided the energy for synthesis simply as a consequence of ligand binding. An interaction free energy between the free energy of the binding of Na+ and the free energy of hydrolysis of the phosphate group on the enzyme was estimated. The experiments also suggested a feature of the transport mechanism. This is control by phosphorylation of access pathways from the solutions in contact with the faces of the membrane to an active center for cation binding. In the dephosphoenzyme access would be to the intracellular solution and in the phosphoenzyme access would be to the extracellular solution.

Adenosine Diphosphate↗

Adenosine triphosphate synthesis by electrochemical proton gradient in vesicles reconstituted from purified adenosine triphosphatase and phospholipids of thermophilic bacterium.

Vesicles were reconstituted from a purified dicyclohexyl-carbodiimide-sensitive ATPase complex (TF0-F1) and phospholipids of a thermophilic bacterium PS3. These vesicles synthesized ATP from ADP and Pi with energy from an electrochemical proton gradient (delta-micronH+) formed by a pH gradient and an electrical potential across their membranes. Maximal ATP synthesis was achieved by incubating the vesicles in malonate at pH 5.5 with valinomycin, and then rapidly transferring them to a solution of pH 8.4 and 150 mM K+. Under these conditons ATP synthesis continued at a decreasing rate for 30 s at 40 degrees. Appreciable formation of ATP (40 to 150 nmol/mg of TF0-F1) occurred at an initial delta-micronH+ above 205 mV and moderate formation at an initial value above 180 mV. ATP hydrolysis by the vesicles produced a delta-micronH+, and the additions of 32Pi and hexokinase to them resulted in 32Pi esterification. Analysis of the time courses of 32Pi esterification and decays of the pH difference and membrane potential, followed using 9-aminoacridine and 8-anilinonaphthalene-1-sulfonate, respectively, as probes, showed a relationship between delta-micronH+ and the rate of ATP synthesis. These results demonstrate that purified TF0-F1 is itself a reversible H+-translocating ATPase of oxidative phosphorylation.

Adenosine Triphosphatases↗

[Expression of uncoupling protein 2 and its relationship to the content of adenosine triphosphate in the nonalcoholic fatty livers of rats fed a high-fat diet].

OBJECTIVE: To investigate the expression of uncoupling protein 2 (UCP2) and its relationship to the content of adenosine triphosphate (ATP) in livers of nonalcoholic fatty liver disease (NAFLD) rats fed a fat-rich diet. METHODS: To produce a NAFLD model, a fat-rich diet, consisting of 10% lard oil + 2% cholesterol, was given to Sprague-Dawley rats for a period of 8, 12, 16 and 24 weeks. The normal control rats were fed normal diets. The expressions of UCP2 in the liver were detected by immunohistochemistry and semi-quantitative RT-PCR. The content of ATP of liver was measured by fluorometry. RESULTS: Simple fatty livers were observed in the model group after 8 weeks. From 12 week to 24 week, the livers of the model group rats gradually progressed from simple steatohepatitis to steatohepatitis with pericellular fibrosis. Both immunohistochemistry and semi-quantitive RT-PCR suggested the up-regulated expression of UCP2 in these NAFLD rat livers. The hepatic expression of UCP2 mRNA in the model group was increased with time, and peaked in 24 week by 4.2 times compared to the control group ( t = 16.474, P < 0.01). The ATP content of livers was significantly reduced in the model group compared with the control group at 16 weeks [(2.97+/-0.48) x 10(-8) micromol/g vs. (2.25+/-0.55) x 10(-8) micromol/g, t = 2.419, P < 0.05] and 24 weeks [(2.97+/-0.48) x 10(-8) micromol/g vs. (1.99+/-0.66) x 10(-8) micromol/g, t = 3.248, P < 0.01]. Furthermore, there was a negative correlation between the UCP2 mRNA expression and the content of ATP in the livers of the NAFLD group (r = -0.93, P < 0.01). CONCLUSIONS: The rat model of NAFLD could be replicated sucessfully by feeding a fat-rich diet for 24 weeks, and the mRNA and its protein of UCP2 were expressed un-regulated in livers of NAFLD. The increasing UCP2 might play a role in the reduction of ATP content in livers of the NAFLD rats.

Adenosine Triphosphate↗

Fluorometric detection of adenosine triphosphate with 3-hydroxy-4'-(dimethylamino)flavone in aqueous solutions.

An effect of appearance of new band in the excitation spectra of 3-hydroxy-4'-(dimethylamino)flavone (FME probe) in presence of adenosine triphosphate (ATP) is described. Considerable shift of new band up to the red and increase of fluorescence intensity points to the formation of FME-ATP associate, in which FME molecule undergoes to a strong electrostatic stabilization by tetra-charged ATP anion. It is shown the FME anion formation is possible under influence of ATP in the studied conditions. The dynamics of the observed effect is studied in mitochondria. The registered phenomenon allows the quantitative evaluation of ATP concentration in the range of 10(-3)-10(-5) M. In contrast to ATP, other nucleoside phosphates do not give a new band in the excitation spectra of FME probe. This implies the possibility of the in vivo determination of the ATP concentration.

Adenosine Triphosphate↗

Neutrophils-induced increase of adenosine triphosphate depletion in rat neonatal cardiac myocytes with impaired energy metabolism.

Isolated, cultured rat neonatal cardiac myocytes were placed in medium supplemented with mitochondrial respiratory inhibitor potassium cyanide which caused a rapid adenosine triphosphate (ATP) depletion. These myocytes with the impaired energy metabolism ("hypoxia-like state") were exposed to unstimulated human neutrophils. Effect of human neutrophils on the myocytes in the "hypoxia-like state" was quantified as a total change in the amount of ATP in cardiac cells. After 5 hours of incubation of neutrophils with the myocytes in the "hypoxia-like state" an additional decrease (of 50 per cent) in ATP content was observed. Since catalase (which destroys hydrogen peroxide) prevented the further decline in ATP level in the myocytes with impaired energy metabolism, it seem that hydrogen peroxide and possibly their products are responsible for this effect. These results suggest that unstimulated human neutrophils after activation by the contact with injured cardiac cells caused further decrease of ATP level in target cells.

Adenosine Triphosphate↗

Adenosine triphosphate content of Mycobacterium leprae by percoll buoyant density centrifugation.

Thirty nine untreated patients of bacilliferous leprosy with a mean bacteriological index of 4.8 and morphological index of 1.3% formed the study group. Adenosine triphosphate assay was carried out by (i) enzyme treatment method in 18 patients and (ii) percoll buoyant density gradient method in 21 patients. ATP content obtained by percoll buoyant density gradient method was significantly higher than that obtained by enzyme treatment method. Percoll buoyant density centrifugation for purification and isolation of bacilli from human leproma is simplier, quicker and can serve as an alternate method of enzyme treatment.

Adenosine Triphosphate↗