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)

A female infant presented with signs of general muscle hypotonia and increasing hypertrophy of the heart muscle. There was a constant lactic acidosis worsened after glucose intake. Serum lactate levels were increased up to 6.7 mmol/l. Serum alanine levels reached maximum concentrations of 2,800 mumol/l. The patient died after sudden cardiac arrest at 22 months of age. Histology of the heart showed the pattern of foamy myocardial transformation with accumulation of mitochondria and an increased glycogen content. Biochemical analysis of the skeletal muscle and the heart demonstrated signs of a disturbed respiratory chain. The content of cytochrome aa3 protein was decreased in skeletal muscle and heart mitochondria. It is suggested that respiratory chain defects may be the cause of foamy myocardial transformation of the heart.
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PMID:Foamy myocardial transformation in a child with a disturbed respiratory chain. 282 64

Forebrain arterioles were analyzed histochemically to determine the effects of an acute administration of ethanol on key enzymes of aerobic and anaerobic metabolism as well as on the hexose monophosphate shunt in rats. The enzymes were glucose 6-phosphate dehydrogenase, cytochrome oxidase, lactate dehydrogenase, beta-hydroxybutyrate dehydrogenase, and isocitrate dehydrogenase. All enzymes were quantified under two conditions: 1 h and 2 days after ethanol administration. Significant changes were noted in four of the five enzymes measured after 1 h and in all five enzymes when measured 2 days after ethanol administration. Our data suggest that ethanol may cause impaired metabolism in the forebrain microvasculature, which, in turn, may account for some of the characteristic behavioral effects of acute ethanol administration.
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PMID:Ethanol alters microvasculature enzymes in the rat forebrain. 284 97

1. Studies have been made on the effects of dietary copper on the iron and Cu distribution in rats and on the metabolic activity and absorptive capacity of intestines perfused both vascularly and luminally. 2. Rats maintained for 4-5 weeks on a Cu-deficient diet (0.4 microgram Cu/kg) had significantly lower plasma, liver and intestinal Cu concentrations and significantly reduced plasma caeruloplasmin and liver cytochrome c oxidase (EC 1.9.3.1) activity compared with controls receiving a Cu-supplemented diet (5 micrograms Cu/kg). Disturbances in Fe metabolism in Cu-deficient rats were evident as shown by a mild anaemia, significantly elevated hepatic Fe concentrations and hypoferraemia. 3. Intestinal glucose uptake from both the luminal perfusion medium (LPM) and vascular perfusion medium (VPM) was unaffected by Cu deficiency despite a significant (25-30%) reduction in oxygen consumption. This was associated with a 40% decline in mucosal cytochrome c oxidase activity. 4. In studies of Fe absorption, Fe uptake from the LPM was unaffected by Cu deficiency while transfer of Fe to VPM was significantly reduced (50%) compared with control preparations. Addition of apotransferrin (1 g/l) to the VPM was without effect in preparations from control rats but significantly increased the transfer of Fe to the VPM in preparations from Cu-deficient rats without affecting Fe uptake from the LPM. 5. The addition of either human or porcine caeruloplasmin (together with apotransferrin) to the VPM, such that the resultant ferroxidase (EC 1.16.3.1) activity of the VPM supernatant fraction was four to five times that of normal rat plasma, was without effect on either Fe uptake, tissue retention or Fe transfer to the VPM by preparations from either Cu-deficient or control rats. 6. These findings offer no evidence in support of the proposed role for caeruloplasmin with its associated ferroxidase activity in Fe absorption in the rat.
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PMID:Studies on the roles of apotransferrin and caeruloplasmin (EC 1.16.3.1) on iron absorption in copper-deficient rats using an isolated vascularly- and luminally-perfused intestinal preparation. 284 73

Rats were subjected to graded arterial hypoxia while we measured changes in the oxidation level of cytochrome c oxidase (cytochrome aa3) in the brain by a non-invasive, optical technique. The experiments were terminated at different arterial oxygen tensions (hypoxic levels) and the in vivo observations were compared with in vitro measured changes in metabolites known to reflect limitations in cellular aerobic energy production, e.g. glucose, pyruvate, lactate, phosphocreatine, ATP and ADP. Using absorption changes at 605 nm, in vivo cytochrome aa3 was 46% reduced in normoxia as determined by the range between the maximal oxidation level attained with animals breathing 85% O2 + 15% CO2 and maximal reduction with anoxia (100% N2). Hypoxia reduced cytochrome aa3 to levels of 52, 67, 76, and 84% at mean PaO2 values of 53, 39, 35 and 28 mm Hg, respectively. These increases in reduced cytochrome correlated significantly (r = 0.94) with cortical phosphocreatine depletion, lactate production, and increases in the lactate/pyruvate ratio. However, there were no significant changes in ATP or ADP. Rats did not survive below an FIO2 of 7% because of a precipitous fall in arterial blood pressure. Hypoxically-induced cerebral isoelectricity was coincident with a 50% increase in the cytochrome reduction level (to 73% of the total range defined above). Our results indicate that in vivo monitoring of the reduction level of cytochrome aa3 provides an early, continuous, and direct measure of intracellular oxygen insufficiency at levels which adversely affect aerobic energy production.
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PMID:Energy metabolism and in vivo cytochrome c oxidase redox relationships in hypoxic rat brain. 286 74

Exogenous addition of hemin to glucose-repressed cells of Saccharomyces cerevisiae stimulates the incorporation of amino acid into cytoplasmic proteins twofold. There was no significant change in the synthesis of total cytoplasmic RNA whereas a 40% increase in the synthesis of poly(A)-containing RNA was observed upon hemin treatment. Cell-free translation of cytoplasmic mRNAs and immunoprecipitation analysis of the translated products with antibodies against subunit V of cytochrome oxidase and the alpha and beta subunits of F1-ATPase reveals that there is an eightfold enrichment of the mRNA for subunit V of cytochrome oxidase upon hemin treatment. The effect of hemin on the alpha and beta subunits of F1-ATPase is only marginal, suggesting a differential role for heme in the synthesis of hemoproteins and nonheme proteins during glucose repression.
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PMID:Role of exogenous hemin in the synthesis of hemoproteins and nonheme proteins during glucose repression in Saccharomyces cerevisiae. 287 92

Three different types of amperometric enzyme electrode are described. The first type uses a conducting organic-salt electrode to oxidize NADH. Results for sensors for ethanol and for bile acids are presented. In the second type of sensor, flavoenzymes are directly oxidized on the surface of the conducting organic-salt electrode. Results for five different enzymes are described. The mechanism of the enzyme oxidation is discussed and the reaction is shown to take place by heterogeneous redox catalysis and not by homogeneous mediation. The enzymes are strongly adsorbed on the electrode; microelectrodes for in vivo studies can be constructed without a membrane. Results for in vivo studies of changing glucose levels in the brain of a freely moving rat are presented. The third type of sensor is designed to measure low levels of toxic gases such as H2S and HCN. This is done by monitoring the inhibition by the toxic gas of the activity of the respiratory enzyme cytochrome oxidase.
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PMID:Amperometric enzyme electrodes. 288 25

The scheme for the identification of Gram-negative nonfermenting microorganisms is proposed. The scheme comprises the most important key signs, such as the cytochrome oxidase reaction determined by the method of Gaby and Hadley, the oxidation/fermentation test, maltose oxidation and motility, as well as additional key signs, among them gelatinase activity, the oxidation of 10% lactose, nitratase activity with the liberation of free nitrogen, the utilization of the sources of carbon and energy (glucose and sodium acetate) in limited media containing ammonium salts and nitrates as the sources of nitrogen. Additional tests for the identification of nonfermenting microorganisms similar in their main key signs are also recommended.
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PMID:[Taxonomic identification of gram-negative nonfermenting microorganisms in environmental research]. 298 90

The cultured skin fibroblasts from three patients with lacticacidemia were found to have low rates of 1-[14C]pyruvate oxidation in the face of normal pyruvate dehydrogenase activity. After incubation with 1 mM glucose, these three cell strains also exhibited lactate/pyruvate ratios which were three times greater than those of controls. In two of the patients, both ATP and oxygen consumption in fibroblast mitochondrial preparations was deficient with NAD-linked substrates but normal with succinate and ascorbate/N'N'N'N' tetramethyl phenylene diamine. In the third patient, ATP synthesis in mitochondrial preparations was deficient with all substrates tested. Measurement of Rotenone-sensitive NADH-cytochrome c reductase in mitochondrial preparations from skin fibroblasts showed that two of the patients had 14 and 18%, respectively, of control activity. In the third patient, cytochrome oxidase activity was 15% of that in controls. We conclude that respiratory chain defects can be demonstrated in cultured skin fibroblasts with consistency using a number of different techniques.
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PMID:Respiratory chain defects in the mitochondria of cultured skin fibroblasts from three patients with lacticacidemia. 300 44

The duration of the presumed metabolic depression of syngeneic vena cava to aorta transplants was determined in rats and the site and type of energy metabolism in the vein grafts assessed. The aerobic metabolic activity was measured from the histochemical reactivity of the enzymes, succinate dehydrogenase and cytochrome oxidase, and the anaerobic activity by staining with lactate dehydrogenase. The activity of the hexose-monophosphate shunt was assessed by the histochemical demonstration of glucose-6-phosphate dehydrogenase. Sixteen hours after grafting a pronounced metabolic depression was noted. Recovery occurred 24 hours after transplantation. The most intense staining was from lactate dehydrogenase in the vein grafts and in the non-transplanted veins. At the end of the observation period of four months the grafts were definitely more strongly stained than the non-transplanted veins, with most of the activity in the thickened intima. This layer had a metabolic profile resembling that of the media of the adjacent aorta.
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PMID:Histochemical examination of energy metabolism in aortic vein grafts in rats. 302 37

Measurement of pyruvate and lactate produced from glucose by confluent skin fibroblast cultures from 95 patients with lactic acidemia revealed 10 in whom the lactate/pyruvate ratio (L/P) was increased (L/P = 57 to 232) compared with that observed in control cell lines (L/P = 18 to 35). Mitochondria prepared from these cells revealed two types of respiratory chain defect. In four patients the deficient activity was present in NADH-coenzyme Q reductase (14% to 21% of controls), and in six the deficiency was in cytochrome c oxidase (21% to 28% of controls). The four patients with NADH-coQ reductase deficiency presented early with lactic acidosis, respiratory failure, anorexia, and hypotonia; all four died within 7 months. The group with cytochrome oxidase deficiency had a somewhat later (18 months to 2 years of age) presentation with milder lactic acidemia, but also with hypotonia and anorexia. They had delayed development, beginning to walk and talk at 18 to 24 months, and then slowly regressed. Although an investigation of central nervous system disorders in this latter group has not been possible, the clinical progression fits into the broad category of Leigh disease. We conclude that in these two groups respiratory chain defects can be detected and localized by the use of skin fibroblast cultures.
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PMID:Clinical presentation of mitochondrial respiratory chain defects in NADH-coenzyme Q reductase and cytochrome oxidase: clues to pathogenesis of Leigh disease. 302 93


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