Search results for "adenosine triphosphate"
showing 10 items of 232 documents
Xanthine oxidase is involved in exercise-induced oxidative stress in chronic obstructive pulmonary disease
1999
In the present study, we hypothesized that exhaustive exercise in patients with chronic obstructive pulmonary disease (COPD) results in glutathione oxidation and lipid peroxidation and that xanthine oxidase (XO) contributes to free radical generation during exercise. COPD patients performed incremental cycle ergometry until exhaustion with (n = 8) or without (n = 8) prior treatment with allopurinol, an XO inhibitor. Reduced (GSH) and oxidized glutathione (GSSG) and lipid peroxides [malondialdehyde (MDA)] were measured in arterial blood. In nontreated COPD patients, maximal exercise (approximately 75 W) resulted in a significant increase in the GSSG-to-GSH ratio (4. 6 +/- 0.9% at rest vs. 9.…
TORC1 Inhibition by Rapamycin Promotes Antioxidant Defences in a Drosophila Model of Friedreich’s Ataxia
2015
Friedreich's ataxia (FRDA), the most common inherited ataxia in the Caucasian population, is a multisystemic disease caused by a significant decrease in the frataxin level. To identify genes capable of modifying the severity of the symptoms of frataxin depletion, we performed a candidate genetic screen in a Drosophila RNAi-based model of FRDA. We found that genetic reduction in TOR Complex 1 (TORC1) signalling improves the impaired motor performance phenotype of FRDA model flies. Pharmacologic inhibition of TORC1 signalling by rapamycin also restored this phenotype and increased the lifespan and ATP levels. Furthermore, rapamycin reduced the altered levels of malondialdehyde + 4-hydroxyalke…
Hypothermic Oscillating Liver Perfusion Stimulates ATP Synthesis prior to Transplantation
1998
Abstract Background. ATP and glycogen depletion often have been demonstrated during cold storage of the liver prior to transplantation. Suppression of events that lead to metabolic depression and to lipid peroxidation could contribute to improvement of liver preservation. A new method of liver preservation for transplantation is therefore suggested, an oscillating oxygenated hypothermic liver perfusion. Methods. Biochemical analysis of liver tissue samples and perfusate after 10 h of perfusion by the presented oscillating perfusion model were compared with results after continuous liver perfusion for 10 h as well as with data derived from cold-stored livers over a period of 10 h. Particular…
Mildronate, the inhibitor of l-carnitine transport, induces brain mitochondrial uncoupling and protects against anoxia-reoxygenation
2013
Abstract The preservation of mitochondrial function is essential for normal brain function after ischaemia-reperfusion injury. l -carnitine is a cofactor involved in the regulation of cellular energy metabolism. Recently, it has been shown that mildronate, an inhibitor of l -carnitine transport, improves neurological outcome after ischaemic damage of brain tissues. The aim of the present study was to elucidate the mitochondria targeted neuroprotective action of mildronate in the model of anoxia-reoxygenation-induced injury. Wistar rats were treated daily with mildronate ( per os ; 100 mg/kg) for 14 days. The acyl-carnitine profile was determined in the brain tissues. Mitochondrial respirati…
Comparative study of the effects of chloral hydrate and trichloroethanol on cerebral metabolism
1973
The isolated perfused rat brain was used for a comparative study of the effects of chloral hydrate and trichloroethanol on cerebral energy metabolism. After a perfusion period of 30 min the brain levels of the following substrates and metabolites were measured spectrophotometrically: P-creatine, creatine, ATP, ADP, AMP, glycogen, glucose, glucose-6-P, fructose diphosphate, α-glycero-P, dihydroxyacetone-P, pyruvate, lactate, glutamate, α-ketoglutarate and ammonia. Furthermore, the concentration of chloral hydrate and trichloroethanol in the isolated brain and in the perfusion medium was measured colorimetrically. Little more than 10% of chloral hydrate in the isolated brain and in the perfus…
Cannabinoid type 1 receptor blockade promotes mitochondrial biogenesis through endothelial nitric oxide synthase expression in white adipocytes
2008
OBJECTIVE—Cannabinoid type 1 (CB1) receptor blockade decreases body weight and adiposity in obese subjects; however, the underlying mechanism is not yet fully understood. Nitric oxide (NO) produced by endothelial NO synthase (eNOS) induces mitochondrial biogenesis and function in adipocytes. This study was undertaken to test whether CB1 receptor blockade increases the espression of eNOS and mitochondrial biogenesis in white adipocytes. RESEARCH DESIGN AND METHODS—We examined the effects on eNOS and mitochondrial biogenesis of selective pharmacological blockade of CB1 receptors by SR141716 (rimonabant) in mouse primary white adipocytes. We also examined eNOS expression and mitochondrial biog…
Suitability of the isolated perfused rat brain for studying effects on cerebral metabolism
1972
The concentrations of P-creatine, creatine, ATP, ADP, AMP, glycogen, glucose, glucose-6-P, fructose diphosphate, dihydroxyacetone-P, α-glycero-P, lactate and pyruvate were measured in the isolated perfused rat brain as well as in rat brain in vivo. Similar levels were observed in the isolated brain and in intact animals, and the values measured were in good accordance with those described in the literature. Only the pyruvate and lactate content were significantly higher in the isolated brain but the lactate/pyruvate ratio remained unchanged. An anesthetic or ischemia caused just the same effects on energy metabolism of the isolated rat brain as described for intact animals. Thus, 1.5 mM phe…
Exercise and recovery in frog muscle: metabolism of PCr, adenine nucleotides, and related compounds
1996
The effects of exercise (swimming), fatigue, and recovery on the intracellular pH (pHi), energy-rich phosphates, and related metabolites were studied in the gastrocnemius muscle of common frogs (Rana temporaria) at 20 degrees C. Exercise caused a rapid decrease in the content of phosphocreatine (PCr) and a corresponding increase in that of Pi. The ATP level remained virtually constant for 1 min; its precipitous decrease during the following minute was associated with a rise in the contents of inosine 5'-monophosphate (IMP) and NH4+, indicating a marked activation of AMP deaminase. Five minutes of swimming caused severe fatigue, which was correlated with decreases in muscle PCr (-85%), ATP …
A New Model of Oxidative Stress in Rat Pups
2007
<i>Background:</i> With current evidence, no specific oxygen concentration can yet be recommended in the resuscitation of the depressed term neonate. <i>Objectives:</i> To design a neonatal rat model of resuscitation that mimics birth hypoxia and allows the study of the effects of resuscitation on outcome. <i>Methods:</i> Several key determinants were established utilizing P12 Sprague-Dawley rat pups. These include the ventilatory settings necessary to maintain normocarbic conditions and the amount and duration of hypoxia required to cause significant disruption of oxidative metabolism in the subjects’ brains. Biochemical and cellular markers of oxidative…
Neurotransmitters adenosine triphosphate and noradrenaline induce nitric oxide release in rat vas deferens.
2000
1. In rat vas deferens, electrical field stimulation (EFS) evoked a muscular biphasic tetrodotoxin (TTX)-sensitive contractile response. 2. The amplitude of this response increased with the frequency of stimulation. 3. After each stimulation, nitric oxide (NO) release was assayed and found to be released in a frequency-dependent manner. 4. NO release also occurred after treatment with exogenous neurotransmitters, adenosine 5'-triphosphate (ATP) and noradrenaline (NA). 5. Prazosin and pyridoxalphosphate-6-azophenyl-2',4'-disulphonic acid (PPADS), respective antagonists of alpha1-adrenoceptors and P2x purinoceptors, inhibited NO release induced by NA and ATP. Both prazosin and PPADS inhibited…