Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:1.9.3.1 (cytochrome oxidase)
8,822 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The effect of hypoxia and post-hypoxic recovery were studied in gastrocnemius muscle of young-adult and mature beagle dogs. Furthermore, the possible interference of pharmacological treatment with nicergoline was evaluated in these conditions. Muscular glycolytic fuels, intermediates and end-products (glycogen, glucose, glucose 6-phosphate, pyruvate, lactate), Kreb's cycle intermediates (citrate, alpha-ketoglutarate, succinate, malate) and related free amino acids (glutamate, alanine), ammonium ion, energy store and mediators (ATP, ADP, AMP and creatine phosphate), and the energy charge potential were evaluated. Furthermore, in the crude extract and/or mitochondrial fraction of another portion of the same gastrocnemius muscle the maximum rate (Vmax) of some muscular enzymes related to the anaerobic glycolytic pathway (hexokinase, lactate dehydrogenase), the Kreb's cycle (citrate synthase, malate dehydrogenase), the aminoacid pool related to the Krebs' cycle (glutamate dehydrogenase and aspartate aminotransferase), the electron transfer chain (cytochrome oxidase) and NAD+/NADH exchanges (total NADH cytochrome c reductase) was evaluated. Some glycolytic metabolites and Krebs' cycle intermediates were modified by acute hypoxia, while free amino acids and energy mediators remained practically unchanged. The pharmacological treatment maintained the glucose and succinate muscular concentrations within the normal range, during hypoxia. The behaviour of muscular metabolites during hypoxia and/or post-hypoxic recovery is an age-related event. In fact, only in young-adult animals did the altered values return to normal in post-hypoxic recovery. In the present experimental conditions, only minor changes were observed as far as muscular enzyme activities are concerned. In any case, some enzyme activities tested showed different Vmax in young-adult dogs in comparison with mature ones.
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PMID:Effect of hypoxia, aging and pharmacological treatment on muscular metabolites and enzyme activities. 322 9

We studied energy metabolism after experimental subarachnoid hemorrhage in rats. Four different cerebral areas were tested: frontal cortex, occipital cortex, hippocampus, and brainstem. Vmax of the following enzymatic activities was evaluated: in the homogenate: hexokinase, phosphofructokinase, and lactate dehydrogenase for the glycolytic pathway, and glucose-6-phosphate dehydrogenase for the hexose monophosphate shunt; in the purified nonsynaptic mitochondria: NAD+-isocitrate dehydrogenase, citrate synthase, and succinate dehydrogenase for the Krebs cycle, and cytochrome oxidase for the electron transfer chain. We also evaluated some parameters related to the respiration of nonsynaptic mitochondria (State 3, State 4, uncoupled state, respiratory control ratio, and ADP:O ratio). Subarachnoid hemorrhage did not significantly affect Vmax of the enzymatic activities related to anaerobic and aerobic metabolism; however, mitochondrial respiration was affected, particularly in the presence of NADH-producing substrates (glutamate + malate).
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PMID:Bioenergetics of different brain areas after experimental subarachnoid hemorrhage in rats. 335 25

Cerebral forebrain arterioles and neuropil were analyzed histochemically to determine the effects of chloral hydrate anesthesia on key enzymes of aerobic and anaerobic metabolism, as well as the hexose monophosphate shunt in rats. Significant decreases were observed in cytochrome oxidase, and beta-hydroxybutyrate dehydrogenase in arterioles, while glucose-6-phosphate dehydrogenase and isocitric dehydrogenase showed a significant increase and lactate dehydrogenase showed no significant change. In the neuropil, cytochrome oxidase, isocitrate dehydrogenase and glucose-6-phosphate dehydrogenase showed significant increases following chloral hydrate administration, while beta-hydroxybutyrate dehydrogenase and lactate dehydrogenase showed no significant changes. These data suggest that surgical anesthetic levels of chloral hydrate can impair forebrain metabolism which may lead to altered electrophysiological responses.
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PMID:Chloral hydrate anesthesia alters cerebral enzymes in the rat. A histochemical study. 343 84

Left ventricular arterioles from Sprague-Dawley rats were analyzed histochemically to determine the effects of halothane administration on key enzymes of aerobic and anaerobic metabolism, as well as on key enzymes of the hexose monophosphate shunt. Significant decreases occurred in cytochrome oxidase (-42%) and beta-hydroxybutyrate dehydrogenase (-57%). No significant changes were observed in isocitrate dehydrogenase, glucose-6-phosphate dehydrogenase, or lactate dehydrogenase. These data suggest that anesthetic levels of halothane can cause impaired metabolism in the coronary microvasculature.
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PMID:Halothane depletes cardiac microvasculature enzymes in the rat. 343 87

2-Bromohydroquinone (BHQ) is a nephrotoxic metabolite of bromobenzene and a model toxic hydroquinone. The primary goal of these studies was to determine whether BHQ produces toxicity in rabbit renal proximal tubules by inhibiting mitochondrial function. BHQ induces a specific sequence of cellular events. Initially there was decrease in tubular glutathione content followed by a decrease in nystatin-stimulated ouabain-sensitive respiration. A decrease in cell viability, as measured by a decrease in lactate dehydrogenase retention, was late event. Associated with the decrease in respiration was a decrease in intracellular ATP content. Probing of mitochondrial function in the tubule revealed that BHQ did inhibit mitochondrial function in a somewhat selective manner. State 3 respiration was inhibited prior to changes in the rate of electron flow through cytochrome c-cytochrome oxidase. It is postulated that BHQ may initially inhibit state 3 respiration by inhibiting the adenine nucleotide translocator and/or the F1-ATPase.
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PMID:Mitochondrial toxicity of 2-bromohydroquinone in rabbit renal proximal tubules. 366 Apr 11

The adaptation to repeated periods of intermittent normobaric hypoxia (oxygen:nitrogen = 10:90, 12 hr daily for 5 days) of some specific enzymatic activities related to energy metabolism has been observed in different rat brain areas (cerebral cortex, hippocampus, corpus striatum, hypothalamus, cerebellum, and medulla oblongata). The evaluation of the maximum rate (Vmax) of the enzymes was carried out on: the homogenate "in toto," the nonsynaptic mitochondrial fraction, and the crude synaptosomal fraction. The adaptation to intermittent normobaric hypoxic exposure was characterized by significant modifications of some enzyme activities in the homogenate "in toto" (decrease of hexokinase activity in cerebellum), in the nonsynaptic mitochondrial fraction (increase of succinate dehydrogenase activity in corpus striatum and decrease of cytochrome oxidase activity in cerebral cortex), and, particularly, in the synaptosomal fraction (decrease of cytochrome oxidase activity in cerebral cortex, hippocampus, corpus striatum, and cerebellum, and decrease of malate dehydrogenase and lactate dehydrogenase activity in cerebellum). The adaptation to normobaric intermittent hypoxia differs according to the brain area, subcellular fraction, and enzyme activity tested.
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PMID:Brain enzyme adaptation to mild normobaric intermittent hypoxia. 376 87

Cytosolic epoxide hydrolase (cEH) activity has been determined in liver and various extrahepatic tissues of male Sprague-Dawley rats using trans-stilbene oxide (TSO) and trans-ethylstyrene oxide (TESO) as substrates. Large interindividual differences in the specific activity of cytosolic epoxide hydrolase in the liver from more than 80 individual rats were observed varying by a factor of 38. In a randomly selected group of five animals liver cEH varied by a factor of 3.9 and kidney cEH by a factor of 2.7, whereas liver microsomal epoxide hydrolase and lactate dehydrogenase showed only very low variations (1.4- and 1.1-fold, respectively). The individual relative activity of kidney cEH was related to that of the liver. Cytosolic epoxide hydrolase activity was present in all of six extrahepatic rat tissues investigated. Interestingly specific activities were very high in the heart and kidney (higher than in liver), followed by liver greater than brain greater than lung greater than testis greater than spleen. TSO and TESO hydrolases in subcellular fractions of rat liver were present at highest specific activities in the cytosolic and the heavy mitochondrial fraction. As indicated by the marker enzymes, catalase, urate oxidase and cytochrome oxidase, this organelle-bound epoxide hydrolase activity may be of peroxisomal and/or mitochondrial origin. In the microsomal fraction, TSO and TESO hydrolase activity is very low, whereas STO hydrolase activity is highest in this fraction and very low in cytosol. In kidney, subcellular distribution is similar to that observed in liver. None of the commonly used inducers of xenobiotic metabolizing enzymes caused significant changes in the specific activities of rat hepatic cEH (trans-stilbene oxide, alpha-pregnenolone carbonitrile, 3-methylcholanthrene, beta-naphthoflavone, isosafrole, butylated hydroxytoluene, 2,3,7,8-tetrachlorodibenzo-p-dioxin, dibenzo[a,h]anthracene, phenobarbitone). However, clofibrate, a hypolipidemic agent, very strongly induced rat liver cEH (about 5-fold), whereas microsomal epoxide hydrolase activity was not affected. Specific activity of kidney cEH was increased about 2-fold.
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PMID:Distribution and inducibility of cytosolic epoxide hydrolase in male Sprague-Dawley rats. 376 23

In porcine areolar placental epithelia, the following enzymes were demonstrated by histochemical methods after 30, 58, 80, 100, and 110 d of pregnancy, respectively: beta-N-acetyl-hexosaminidase, beta-galactosidase, beta-glucuronidase, alpha-mannosidase, acid phosphatase, alkaline phosphatase, nonspecific esterases, cytochrome oxidase, 5-nucleotidase, leucine aminopeptidase, adenosine triphosphatase, diaphorases (NADH, NADPH), glucose-6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase, succinate dehydrogenase, isocitrate dehydrogenase (NAD, NADP), beta-hydroxybutyrate dehydrogenase, glycero-3-phosphate dehydrogenase, NAD-glycero-3-phosphate dehydrogenase, glutamate dehydrogenase (NAD, NADP), lactate dehydrogenase. The results show that the enzyme activities remained almost unchanged during the period of investigation. Of the dehydrogenases, the diaphorases as well as succinate and lactate dehydrogenase demonstrated generally an intensive activity within the epithelia. The activity of the other dehydrogenases was only low. The activity of unspecific esterase was very intensive within the uterine epithelia but remarkably low within chorionic epithelia. Contrarily, the reaction of adenosine triphosphatase was more intensive within chorionic than uterine epithelia. All investigated glucosidases reacted distinctly positive within chorionic epithelia, but only beta-N-acetyl-hexosaminidase and beta-galactosidase in uterine epithelia. The high activity of acid phosphatase, especially within the chorionic epithelium, seems to be connected with uteroferrin, an iron-binding protein. The histochemical results are discussed in context with the function of the areolae in histiotrophic nutrition and iron transport.
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PMID:[Enzyme-histochemical studies of the pig placenta. II. Histotopics of enzymes in the areolar placenta epithelium]. 392 41

Muscular glycolytic fuels, intermediates and end-products (glycogen, glucose, glucose-6-phosphate, pyruvate, lactate), Krebs cycle intermediates (citrate, alpha-ketoglutarate, succinate, malate), related free amino acids (glutamate, alanine), ammonia, energy store (creatine phosphate), energy mediators (ATP, ADP, AMP) and energy charge potential were evaluated. Furthermore the maximum rate (Vmax) of the following muscular enzyme activities was evaluated in the crude extract and/or mitochondrial fraction: for the anaerobic glycolytic pathway: hexokinase, phosphofructokinase, pyruvate kinase, lactate dehydrogenase; for the tricarboxylic acid cycle: citrate synthase, malate dehydrogenase; for the electron transfer chain: total NADH cytochrome c reductase, cytochrome oxidase. The rat gastrocnemius muscles were analyzed in normoxia and after repeated, alternate hypoxic and normoxic exposures (12 hours of hypoxia daily; for 5 days). Naftidrofuryl was administered daily at three different doses: 10, 15 and 22.5 mg/kg i.m., 30 min before the beginning of the experimental hypoxia. The biochemical adaptation to intermittent normobaric hypoxic-normoxic exposures was characterized by the decrease of the muscular contents of creatine phosphate, citrate, alpha-ketoglutarate and glutamate. This adaptation occurred in absence of significant changes in the Vmax of the muscle enzymes tested. By naftidrofuryl treatment, in gastrocnemius muscle from hypoxic rats both alpha-ketoglutarate and creatine phosphate contents maintained normal values, while glutamate concentration remained reduced to subnormal values. With the exception of hexokinase, naftidrofuryl treatment did not modify the Vmax of marker enzymes related to energy transduction.
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PMID:Adaptation of skeletal muscle energy metabolism to repeated hypoxic-normoxic exposures and drug treatment. 401 59

Muscular glycolytic fuels, intermediates and end-products (glycogen, glucose, glucose-6-phosphate, pyruvate, lactate), Krebs cycle intermediates (citrate, alpha-ketoglutarate, succinate, malate), related free amino acids (glutamate, alanine), ammonia, energy store (creatine phosphate), energy mediators (ATP, ADP, AMP) and energy charge potential were evaluated. Furthermore the maximum rate (Vmax) of the following enzyme activities was evaluated in the crude extract and/or mitochondrial fraction: for the anaerobic glycolytic pathway: hexokinase, phosphofructokinase, pyruvate kinase, lactate dehydrogenase; for the tricarboxylic acid cycle: citrate synthase, malate dehydrogenase; for the electron transfer chain: total NADH cytochrome c reductase, cytochrome oxidase. The rat gastrocnemius muscles were analysed in normoxia and after normobaric intermittent hypoxia (12 hours continuously daily; for 5 days). Cytidine and/or uridine were administered daily at the dose of 120 mg/kg, i.p., 30 min before the beginning of the experimental hypoxia. The intermittent normobaric hypoxia induced a biochemical adaptation characterized by the decrease of the muscular contents of creatine phosphate, citrate, alpha-ketoglutarate and glutamate. This adaptation occurred in the absence of significant changes in the Vmax of the tested muscle enzymes. In gastrocnemius muscle from hypoxic rats, the two biological pyrimidines tested induced various discrete, but often related, modifications of the contents of some Krebs cycle intermediates (i.e., alpha-ketoglutarate, malate) and related free amino acids (i.e., glutamate, alanine). In any case, the treatment with cytidine and/or uridine did not modify the Vmax of marker enzymes related to energy transduction.
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PMID:Modification of the skeletal muscle energy metabolism induced by intermittent normobaric hypoxia and treatment with biological pyrimidines. 402 89


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