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PubMed1979

Utilization of adenosine triphosphate in rat mast cells during histamine release induced by the ionophore A23187.

The role of endogenous adenosine triphosphate (ATP) in histamine release from rat mast cells induced by the ionophore A23187 in vitro has been studied. 2 The amount of histamine released by calcium from rat mast cells primed with the ionophore A23187 was dependent on the ATP content of the mast cells. 3 In aerobic experiments a drastic reduction in mast cell ATP content was found during the time when histamine release induced by A23187 takes place. 4 Anaerobic experiments were performed with metabolic inhibitors (antimycin A, oligomycin, and carbonyl cyanide p-trifluorometroxyphenylnydrazone), which are known to block the energy-dependent calcium uptake by isolated mitochondria. The mast cell ATP content was reduced during A23187-induced histamine release under anaerobic conditions in the presence of glucose. This indicates an increased utilization of ATP during the release process. 5 The observations are consistent with the view that energy requiring processes are involved in ionophore-induced histamine release from rat mast cells although part of the ATP reduction in the aerobic experiments may be due to an uncoupling effect of calcium on the oxidative phosphorylation.

Adenosine Triphosphate↗
PubMed1993

Selective killing of murine leukemic cells by adenosine triphosphate (ATP): a study of the value of autologous bone marrow transplantation.

To assess the value of adenosine triphosphate (ATP) for ex vivo purging of leukemic cells in autologous bone marrow transplantation, its biological effects on the murine leukemic cell lines (WEHI3B and L1210) and normal murine bone marrow hemopoietic stem cells (CFU-C and CFU-S) were studied. After treatment with 4 mM of ATP for 6 h, the number of viable WEHI3B cells decreased to less than 0.1% of that of the control. Furthermore, 3H-thymidine incorporations were also completely inhibited in both WEHI3B cells and L1210 cells. These phenomena were related to the concentration and exposure period of ATP. Treatment of bone marrow mononuclear cells with ATP under the same condition reduced the number of CFU-C, day 9 CFU-S and day 12 CFU-S to only 58.5 +/- 8.7%, 92.6 +/- 8.2% and 83.5 +/- 28.5%, respectively, with no change in the number of marrow nucleated cells. Although the effect of ATP is not entirely specific to leukemic cells, these findings provide evidence that ATP is useful for purging residual tumor cells in autologous bone marrow transplantation.

Adenosine Triphosphate↗
PubMed1984

Comparison of the biphasic excitatory junction potential with membrane responses to adenosine triphosphate and noradrenaline in the rat anococcygeus muscle.

The effects of field stimulation and ionophoretic application of adenosine triphosphate (ATP) and noradrenaline were studied in the rat anococcygeus by means of an intracellular microelectrode. Field stimulation at room temperature produced three types of electrical membrane response: (a) a 'fast' excitatory junction potential (e.j.p.) which had a latency of less than 100 ms and a time to peak of 300 ms; (b) a 'slow' e.j.p. which had a latency of several hundred ms and a time to peak of 1-2 s, and (c) an inhibitory junction potential (i.j.p.) which had a time to peak of about 1.5 s. All three responses were blocked by tetrodotoxin. The ionophoretic application of ATP produced both monophasic and biphasic depolarizations; these responses had a latency of less than 30 ms and a time to peak of 150-300 ms. In contrast, ionophoretically-applied noradrenaline produced a depolarization which had a mean latency of 471 ms and a time to peak of 861 ms. The 'slow' e.j.p. and the noradrenaline-induced depolarization were blocked by prazosin whereas the 'fast' e.j.p. and the ATP responses were resistant to this antagonist and also to atropine. These results are further evidence that the 'fast' e.j.p. in some smooth muscle tissues is mediated by ATP.

Adenosine Triphosphate↗
PubMed1994

Synergistic action of histamine and adenosine triphosphate on the response to noradrenaline in rabbit pulmonary artery smooth muscle cells.

The interaction between histamine, adenosine triphosphate (ATP) and noradrenaline was studied with the perforated-patch technique in single cells isolated from the rabbit pulmonary artery. In these cells all of the agents activated caffeine-sensitive currents. In potassium-free conditions at a holding potential of -50 mV bath applied histamine, in concentrations that did not produce a response, greatly enhanced the magnitude of inward currents evoked by ionophoretic application of noradrenaline. These inward currents were calcium-activated chloride currents, ICl(Ca). In potassium-containing solutions at a holding potential of 0 mV, bath applied histamine potentiated the outward currents (calcium-activated potassium currents (IK(Ca)) induced by noradrenaline. This synergistic action was rapid in onset, sustained during the continued presence of histamine and reversible. Bath application of noradrenaline inhibited the response to ionophoretically applied noradrenaline but not the caffeine-induced currents. ATP also stimulated ICl(Ca) and IK(Ca) through a mechanism dependent on the caffeine-sensitive intracellular calcium store and also potentiated the currents activated by noradrenaline. It is concluded that one explanation for the phenomenon of potentiation in smooth muscle is convergence of several distinct pharmacological receptors to a common cellular mechanism.

Adenosine Triphosphate↗
PubMedDate not supplied

Arterial ketone body ratio and adenosine triphosphate concentration in hepatic ischemia and reperfusion.

BACKGROUND/AIMS: The arterial ketone body ratio (AKBR) and the cellular adenosine triphosphate (ATP) concentration have been proposed as indicators of liver function. However, recent studies of the utility of the AKBR as a biochemical marker have been called into question. Furthermore, there is no practical data defining the relationship between ATP concentration and ischemia-reperfusion (IR) changes during liver surgery. METHODOLOGY: The relationship of the AKBR and arterial ATP concentration to IR during hepatectomy was investigated. In 20 patients who underwent hepatectomy, arterial acetoacetate, beta-hydroxybutyrate, and ATP concentrations were measured. The ratio of acetoacetate to beta-hydroxybutyrate (AKBR) was calculated before and after vascular occlusion. RESULTS: The AKBR 15 minutes after clamping was lower than the preclamping values in all of the patients. It increased after unclamping, returning toward the preclamping levels. An AKBR of less than 0.5 prior to clamping did not correlate with preoperative hepatocellular function. An AKBR of less than 0.7 throughout IR was not a consistent risk factor for postoperative complications and liver dysfunction. The arterial ATP concentration did not correlate with the changes during IR or with preoperative hepatocellular function. CONCLUSIONS: Although the AKBR changed during IR as a general indicator of cellular activity, the absolute value of the AKBR was not an accurate predictor of liver function. The arterial ATP concentration also was not a suitable clinical biochemical marker of hepatic function.

Adenosine Triphosphate↗
PubMed1994

Adenosine triphosphate release by osmotic shock and hemoglobin A1C in diabetic subjects' erythrocytes.

We investigated the significance of adenosine triphosphate (ATP) release from diabetic subjects' red blood cells (RBCs) following osmotic shock (OS) and its possible relationship with hemoglobin A1C (HbA1C) and with the RBC membrane protein skeleton. RBCs from type I (insulin-dependent [IDDM]) and type II (non-insulin-dependent [NIDDM]) diabetic subjects and age- and sex-matched control subjects were submitted to OS using NaCl solutions (from 0.9% to 0.045% final concentration). ATP release values were determined by the bioluminescent method. For pattern study, they were expressed both as absolute values and as percentages (%) of ATP maximum release (at 0.045% NaCl solution). Twenty-seven IDDM and 25 NIDDM subjects and two control groups were investigated. ATP content in RBCs was 2.08 +/- 0.19 pmol/10(4) RBC in IDDM and 1.23 +/- 0.20 pmol/10(4) RBC in NIDDM subjects. The ATP content of IDDM subjects' RBCs was significantly higher than that of the corresponding control group. ATP release at 0.49% NaCI OS, both as absolute value and as percentage value, was significantly lower in both diabetic groups, and ATP% was inversely correlated with HbA1" (IDDM: r = -.489, P < .01; NIDDM: r = -.654, P < .01), suggesting a possible relationship between Hb glycation, RBC membrane protein skeleton glycation, and its influence on ATP release by OS. In conclusion, the proposed method seems useful for measuring RBC ATP content and, at the same time, for monitoring the leak effect of the RBC membrane before it bursts.

Adenosine Triphosphate↗
PubMed1996

[The evaluation of adenosine triphosphate bioluminescence assay for chemosensitivity testing of ovarian cancer cell line].

OBJECTIVE: To assess the efficacy of adenosine triphosphate (ATP) assay for chemosensitity testing of ovarian cancer cell line and to compare its predicting value with that of diphenyltetrazolium bromide (MTT) test. METHODS: By using ATP assay and MTT test the cytotoxic effect of 7 anticancer drugs on ovarian cancer cell line AO were determined. The sensitivity and stability of ATP assay were compared with those of MTT test. The optimal time of exposure of the cells to the drugs before doing ATP chemosensitity assay is investigated. RESULTS: (1) The results obtained by ATP assay correlate well with that by MTT test (r = 0.918 1). However, in 90% of the assay samples the cytotoxic effect of the chemotherapeutic agents on cancer cells detected by ATP assay was 10% or more stronger as compared with that determined by MTT test. The difference in sensitivity of the two assays was also demonstrated by the least number of living cells. A change of living cells of 60 per well could be detected by ATP assay while that detected by MTT test should be 200 per well. (2) By repeating the tests of a same batch of samples for 5 times, it revealed that the results obtained by ATP assay was more stable than MTT test. The difference between the sx- (standard error) of the two tests was significant (P < 0.05). (3) The optimal time of exposure of the cancer cells to the anticancer drugs for testing its chemosensitivity was 5 days. CONCLUSIONS: The method of ATP assay for chemosensitivity test is simple and convenient with high sensitivity and stability. It may be used as a new in vitro chemosensitivity test in patients with ovarian cancer.

Adenosine Triphosphate↗
PubMed2001

Performance of batch membrane reactor: Glycerol-3-phosphate synthesis coupled with adenosine triphosphate regeneration.

Glycerol-3-phosphate (G3P) was synthesized from glycerol using glycerol kinase (GK). This reaction requires adenosine triphosphate (ATP) and was coupled with the ATP regeneration reaction using acetate kinase (AK) in a batch-operated ultrafiltration hollow-fiber reactor. By taking into consideration the dynamic nature of the bioreactor performance under non-steady-state conditions, a model for the performance of a batch membrane reactor for G3P synthesis coupled with ATP regeneration was developed and studied. The simulation results showed good agreement with the experimental results. The simulation studies have provided some insight into the process dynamics of the coupled reactions in the reactor system studied. For the reactor operational model used, in which the enzymes are retained in the shell side and the substrates are also initially placed in the shell side, it was found that the substrate concentration in the lumen side increased to a level higher than that in the shell side, and a backdiffusion occurred from the lumen side to the shell side during reactor operation. The ratio of the reaction rate to diffusion rate goes through a sharp peak during the time that the direction of diffusion is reversed. For another reactor operational model, in which the substrates were initially placed in the lumen side and enzymes were retained in the shell side, it was found that the rate-controlling step between the reaction and diffusion was switched during the reactor operation. Initially, the reaction rate increased while the diffusion rate was high and the substrate concentrations increased in the shell side. The ratio of reaction rate to diffusion rate increased to a maximum and remained at a constant level as the diffusion rate decreased to a low level due to the nonlinear characteristics of mass transfer process. This study provides information that is useful for optimization of batch membrane enzyme reactor operation and for a fed-batch-type process with an intermittent feeding strategy for efficient use of substrates.

Acetate Kinase↗
PubMed1996

Inorganic pyrophosphate generation from adenosine triphosphate by cell-free human synovial fluid.

OBJECTIVE: To quantify inorganic pyrophosphate (PPi) production from extracellular adenosine triphosphate (ATP) by human synovial fluids (SF). METHODS: Serial measurements of ATP hydrolysis rate (t1/2) were performed by the luciferase method from a starting concentration of 500 nM in 21 pathologic and one normal cell-free SF samples incubated under physiologic conditions. ATP was then pumped into a sample of each fluid, using the rate constant derived from the t1/2 of that fluid, to provide steady state levels simulating those reported in SF. Trace [32P] gamma ATP was added at the start of the infusion; conversion to [32P] Pi and to [32P] PPi was determined by precipitation of Pi as reduced phosphomolybdate before and after treatment with yeast inorganic pyrophosphatase. Finally, the pumping experiment was repeated and PPi production was calculated from direct measurement of PPi at time zero and at 60 min. PPi hydrolysis was measured in each fluid by [32P] Pi precipitation from [32P] PPi tracer added at time zero. RESULTS: ATP was hydrolyzed by all SF. The mean t1/2 (seconds) in 8 osteoarthritis (OA) samples was 72 s, in 5 calcium pyrophosphate dihydrate (CPPD) 30 s (p < 0.02), in 3 rheumatoid arthritis (RA) 1160 s, in normal 86 s, in 3 olecranon bursal (OB) 54 s, and in 2 total knee replacement fluid samples 17 and 121 s. The major product of ATP hydrolysis was PPi in all but 2 fluids (1 RA, 1 OB), even at lower than steady state levels. At simulated in vivo steady state ATP levels, mean conversion of APT to PPi was stoichiometric in OA and CPPD fluids. PPi hydrolysis was < 4% in all noninflammatory fluids. CONCLUSION: PPi is the major product of extracellular ATP catabolism in most SF. Hydrolysis rates were significantly faster in SF containing CPPD crystals. Mean PPi production by these fluids at simulated in vivo steady state levels was 6-fold that of OA SF (p < 0.01). Hydrolysis of extracellular ATP by ectonucleotide pyrophosphohydrolases can account for all PPi produced by joint issues previously estimated from [32P] PPi pool and turnover studies in human knee joints.

Adenosine Triphosphate↗
PubMed1996

Recovery of adenosine triphosphate tissue levels of grafts preserved by the two-layer method after reperfusion.

Recovery of tissue adenosine triphosphate (ATP) levels after transplantation is very important for graft survival. We examined whether the pancreas grafts preserved by the two-layer method have the ability to synthesize ATP after reperfusion, and this is one of the mechanisms of action for the two-layer method in successful pancreas preservation. After preservation by the two-layer method using Euro-Collins' solution (EC) for 48 h (Group 1, n = 5) or simple cold storage in EC for 48 h (Group 2, n = 5), canine pancreas grafts were autotransplanted. In controls (Group 3, n = 5), canine pancreas grafts were autotransplanted without preservation. Graft viability was judged from graft survival after transplantation. Tissue adenine nucleotide concentrations were measured using high performance liquid chromatography after preservation, before reperfusion, and after 1 and 2 h of reperfusion. Graft survival rates were 5 of 5, 0 of 5, and 5 of 5, in Groups 1, 2, and 3, respectively. However ATP tissue levels in Group 1 were significantly higher compared with those in Group 2 after preservation and before reperfusion, respectively (10.95 +/- 1.52 vs. 2.75 +/- 0.33 and 2.90 +/- 0.51 vs. 2.03 +/- 0.68 mumol/g dry weight, p < 0.01 and p < 0.05, respectively). Total tissue adenine nucleotide levels in Group 1 before reperfusion were 7.41 +/- 1.47 mumol/g dry weight, and there was no significant difference compared with Group 2, 6.64 +/- 2.23 mumol/g dry weight. After reperfusion, there was no significant difference of ATP tissue levels between Groups 1 and 2 (4.07 +/- 1.18 vs. 4.48 +/- 1.32, not significant [NS]) after 1 h of reperfusion. However, after 2 h of reperfusion, tissue ATP levels in Group 1 (6.71 +/- 1.19 mumol/g dry weight) were significantly higher than were those in Group 2 (4.51 +/- 0.51 mumol/g dry weight, p < 0.01) and almost at the same levels as control (6.32 +/- 1.62 mumol/g dry weight). It was clear that recovery of ATP after reperfusion did not depend on the residual nucleotides pool but on the ability of the pancreas graft to synthesize ATP after reperfusion. We conclude that oxygenation of the pancreas graft during preservation by the two-layer method allows for ATP synthesis, which is essential in maintaining cellular integrity and leads to maintaining the graft's ability to synthesize ATP promptly after reperfusion. This is one of the mechanisms of action of the two-layer method in successful pancreas preservation.

Adenosine Triphosphate↗
PubMed1976

Interaction of salicylic acid with adenosine and adenosine triphosphate. Potential mechanism of intensifying acetylsalicylic acid-induced GI blood loss.

Complex formation between salicylic acid and adenosine or adenosine triphosphate in 0.2m phosphate buffer at pH=7 was investigated as a potential factor contributing to the prolongation of acetylsalicylic acid-induced GI blood loss. Spectrophotemetric techniques were used to evalute the complexation. Concerntration dependency of the absorbance decrease was measured at 27 and 37 degrees C. The addition of salicylic acid to either adenosine or adenosine triphosplate solutions appeared also to cause a decrease in surface tension which may play a role in reducing platelet aggregation induced by adenosine diphosphate. The results obtained seem to support the opinion that the mechansim of acetylsalicylic acid-induced GI blood loss is due to a combination of both local and systemic effect.

Adenosine↗
PubMed2000

Characterization of lactic acid formation and adenosine triphosphate consumption in calcium-loaded erythrocytes of broiler chickens.

The formation of lactic acid and consumption of adenosine triphosphate (ATP) were measured in erythrocytes from broiler and White Leghorn chickens with the goal of providing further evidence that lactic acid, a metabolite from glycolysis, is an etiological factor for sudden death syndrome (SDS) in broiler chickens. When loaded with Ca2+, erythrocytes exhibited increased lactic acid concentrations. The effect of Ca2+ loading was significantly faster in broiler erythrocytes. In the absence of adenosine used as an energy-yielding substrate, Ca2+ loading was followed by a reduction in ATP concentrations. The effect was also significantly faster in broiler erythrocytes. Intravenous injection of a 20% lactate solution at 0.1 mL/kg produced SDS-like death of broilers but not White Leghorns. The results obtained in erythrocytes indicate that, in broilers, a greater amount of energy is required for regulation of intracellular Ca2+ concentrations, and, thereby, formation of lactic acid is more accelerated. In addition to the result that intravenous lactate injection caused death in broilers, an elevation of lactic acid concentrations in blood, arising from operation of Ca2+ regulation mechanisms, may predispose broilers to incidence of SDS.

Adenosine Triphosphate↗
PubMed2003

Cellular energetics in hemorrhagic shock: restoring adenosine triphosphate to the cells.

BACKGROUND: This is a review of studies with two agents, glutamine and crocetin, which have been found to enhance recovery of cellular adenosine triphosphate (ATP) and adenosine diphosphate after hemorrhagic shock. METHODS: The studies used a sublethal (30 minutes) reservoir shock model in 300- to 350-g, male, Sprague-Dawley rats, using either ketamine-xylazine or isoflurane anesthesia. Glutamine was given as a 3% (21 mmol/L) solution in Ringer's lactate (630 mg/kg). Crocetin was given as a 500 nmol/L solution in Ringer's lactate (2 mg/kg). RESULTS: Both glutamine and crocetin caused recovery of ATP to baseline levels (9.0 micromol/g) within 60 to 120 minutes after resuscitation. Xanthine levels returned more rapidly to baseline (0.1 micromol/g). Both agents prevented the elevation in apoptosis seen in controls at 24 and 48 hours. CONCLUSION: Glutamine is a metabolic substrate and a precursor of ATP synthesis. Crocetin enhances oxygen diffusivity in plasma. Both agents restore cellular energy stores to normal after hemorrhagic shock and produce a marked diminution in the extent of apoptosis postshock. Their mechanism of action probably involves prevention of mitochondrial damage.

Adenosine Diphosphate↗
PubMed1989

[Studies on the preparation of adenosine triphosphate (ATP) liposomes].

In this paper, a method--improved emulsification vesicles (IEV) was proposed for the preparation of adenosine triphosphate (ATP) liposome. The ATP entrapment ratio reached 38.9% (w/w), which was much greater than that reported in the literature. Thus, IEV is an excellent method which has never been presented. Together with ultrafiltration for removing unentrapped drugs and radiation sterilization, these methods are most meaningful for the production of liposomes in large scale.

Adenosine Triphosphate↗
PubMed1976

The adenosine triphosphate content and lactic acid production of guinea-pig skin after mild heat damage.

The depletion of adenosine triphosphate in skin after mild thermal injury is not large enough to be accounted for by loss of oxidative respiration. Measurement of lactic acid production by skin suggest that glycolysis is less sensitive to heat damage than is oxygen uptake. It is therefore likely that glycolysis makes a large contribution to the relatively high levels of ATP persisting in heat damaged skin.

Adenosine Triphosphate↗
PubMed1997

The in vitro effects of extracellular adenosine triphosphate on the ultrastructure of Trypanosoma cruzi epimastigotes.

Incubation for 24 h in culture medium containing 50 mM adenosine triphosphate (ATP) produces distinct alterations in the ultrastructure of Trypanosoma cruzi epimastigotes, most obvious of which is the formation of large membrane-bound vacuoles in the cytosol. These vacuoles become positive following exposure to the macromolecule horseradish peroxidase (HRP). After a 20-min chase in phosphate-buffered saline (PBS) the HRP-positive vacuoles begin to separate into discrete structures such that after a 60-min chase, obvious reservosomes are identifiable. It is hypothesized that extracellular ATP causes increased permeability of the epimastigote's plasma membrane, resulting in ionic fluxes that, in turn, interfere with the normal formation of reservosomes.

Adenosine Triphosphate↗
PubMed1990

Estimation of adenosine triphosphate utilization of rat mast cells during and after anaphylactic histamine secretion.

Determination of the cellular content of adenosine triphosphate (ATP) and the rate of ATP-synthesis were used to estimate the cellular utilization of ATP in relation to anaphylactic histamine secretion. There was an increased rate of oxidative ATP-synthesis and a decreased cellular ATP content during the time period of histamine secretion and immediately after its completion. During secretion the additional ATP-utilization above the basal level of ATP-synthesis was 0.51 pmol/10(3) cells. 2.5 min after cell activation, the rate of additional ATP-utilization was 0.30 pmol/10(3) cells/min, and the persistent ATP-decrease observed after 30 and 120 min may be due to a decreased rate of oxidative ATP-synthesis.

Adenosine Triphosphate↗