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 postnatal maturation of cytochrome oxidase and lactate dehydrogenase activity was assessed by histochemistry in rats at 8 postnatal stages, P0, P5, P10, P14, P17, P21, P35 and the adult stage. Enzyme activities were revealed on cryostat brain sections with diaminobenzidine for cytochrome oxidase and nitroblue tetrazolium for lactate dehydrogenase. Lactate dehydrogenase activity remained unchanged between P0 and P10, significantly increased in 8 areas of the 14 studied between P10 and P14 and in 6 structures from P14 to P17. These were mainly parietal, auditory and cerebellar cortices, hippocampus, thalamus, hypothalamus and medial geniculate body. There was no further change until P35 and lactate dehydrogenase activity increased then significantly to reach higher adult levels in hippocampus and medial geniculate body. Cytochrome oxidase activity was low from P0 to P10 and increased in 8 regions between P10 and P14. These were all cortices, caudate nucleus, hippocampus, inferior colliculus and genu. Enzyme activity further increased between P14 and P17 in auditory cortex, medial geniculate body and brainstem, did not vary from P17 to P21 but increased by 92 to 371% in all areas between P21 and P35. Cytochrome oxidase activity rose further from P35 to adult stage in hippocampus and medial geniculate body. From birth to adulthood, cytochrome oxidase activity increased 5 to 19 fold and lactate dehydrogenase activity 1.8 to 3.0. The present study shows that there is a quite good correlation between postnatal changes in regional cerebral glucose utilization and activity of enzymes involved in glycolytic and oxidative glucose metabolism in the rat.
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PMID:Quantitative histochemical changes in enzymes involved in energy metabolism in the rat brain during postnatal development. I. Cytochrome oxidase and lactate dehydrogenase. 166 81

We reported a girl with mitochondrial encephalomyopathy, who had various neuromuscular symptoms including dilated cardiomyopathy, generalized convulsions, myoclonus, muscular weakness and growth retardation. Lactate levels in the serum and CSF were elevated. Muscle biopsy showed scattered ragged-red fibers, and complex I (NADH-CoQ reductase) and complex IV (cytochrome c oxidase) were markedly reduced. Although she was treated with coenzyme Q, DL-carnitine and sodium succinate, she died of progressive congestive heart failure at 9 10/12 years of age.
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PMID:[A case of mitochondrial encephalomyopathy with cardiomyopathy due to decreased complex I and IV activities]. 255 57

The goal was to describe the metabolic profile of ganglionic and cortical arteries and arterioles in aging normotensive male rats. Five enzymes indicative of key metabolic pathways in the vessel walls were semiquantitatively evaluated using bright-field histochemical microscopy. Lactate dehydrogenase showed significant reactivity which increased with vessel diameter in cortical and ganglionic vessels in all age groups tested. Succinate dehydrogenase and cytochrome oxidase showed little reactivity in both cortical and ganglionic vessels, suggesting a reduced role for aerobic metabolic pathways. Myosin ATPase reactivity was high in cortical and ganglionic vessels. Only this enzyme showed an increased reactivity that was correlated with the age and diameter of the vessel. Glucose-6-phosphate dehydrogenase reactivity was more pronounced in cortical than ganglionic vessels, suggesting that the hexose-monophosphate-shunt may be more active in the cortical vessels. There were no regional differences in enzyme reactivity throughout the caudatoputamen. In conclusion, both the cortical and ganglionic vessels are metabolically active, with significant anaerobic glycolysis, and reduced, but observable capacity for aerobic metabolism. The decreased myosin ATPase reactivity and the low level of glucose-6-phosphate dehydrogenase reactivity in the ganglionic arterioles of senescent rats may contribute to the susceptibility of these vessels to cerebrovascular accidents.
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PMID:A histochemical study of cerebral cortical vessels and ganglionic vessels of the caudatoputamen in aging normotensive rats. 315 35

1. Responses of enzymic characteristics of gastrocnemius muscle were studied when frogs (Rana pipiens) were exposed to cold environment (4 degrees C). 2. The content of adenosine triphosphate (ATP) decreased significantly after cold exposure. This decrease was greater in starved than in fed frogs. 3. Although the glycogen content did not change, lactate levels were lower in cold-exposed than room-temperature (control) frogs. No change was observed in glycogen and lactate between fed and unfed frogs kept at 4 degrees C for 2 months. Lactate dehydrogenase activity tended to increase during chronic cold exposure, but not significantly. 4. The activities of citrate synthase, cytochrome oxidase, and beta-hydroxyacyl CoA dehydrogenase were higher in gastrocnemius of chronically cold-exposed frogs than in room-temperature controls. This increase was statistically significant only in the muscles of starved frogs; these muscles had the greatest decrease in ATP. 5. It was suggested that chronic cold exposure decreases skeletal muscle ATP content but may not affect glycolysis. The data also suggested that the decrease in ATP content stimulates mitochondrial biogenesis which increases enzyme activities.
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PMID:Effects of exposure to cold on metabolic characteristics in gastrocnemius muscle of frog (Rana pipiens). 326 90

1. A procedure has been developed for the separation of intact metabolically active neuronal and glial cells in bulk from rat cerebral cortex. Separation depended on dispersion of the tissue in a Ficoll medium followed by centrifugation on a discontinuous Ficoll gradient. Up to 1.5x10(7) neuronal cells could be collected from 12 brains within 3hr. The morphological appearance of these cells seemed good, and the fraction was 8.5-fold purified in terms of dry weight. Average dry weight per neuron was 2300mumug. Maximum glial contamination of the neuronal fraction was 11% as determined by carbonic anhydrase measurements. The glial fraction was free from neurons but contained various subcellular contaminants. 2. Concentrations of nucleic acids, phospholipid, protein and phosphoprotein were determined in the separated fractions. The neuronal fraction was richer than the glial in all except phospholipid. Succinate dehydrogenase was equally distributed between neurons and glia but the neuronal fraction was 1.8-fold enriched in cytochrome oxidase. 3. Measurement of respiration by the cells showed an endogenous uptake of 117mmumoles of oxygen/mg./hr. in neurons, and 173mmumoles of oxygen/mg./hr. in glia. Addition of substrate at 10mm stimulated uptake to similar values in both fractions. With glucose it was 390, with pyruvate 355, and with glutamate 215mmumoles of oxygen/mg./hr. This represented a larger stimulation of neuronal than of glial respiration compared with the basal level. 4. Respiration in cell suspensions was 70-80% of that of slices, whereas fractionated tissue homogenates had respiratory rates of only one-third those of the cell suspensions. Lactate dehydrogenase content of cell suspensions was maintained during gradient centrifugation and washing. 5. The possible uses of isolated cell preparations are discussed.
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PMID:Preparation of enriched fractions from cerebral cortex containing isolated, metabolically active neuronal and glial cells. 429 62

Young rats were made iron deficient by feeding them a low-iron diet for 8 wk. Iron deficiency resulted in a 50% decrease in cytochrome c and cytochrome oxidase and a 26% decrease in mitochondrial glycerol-3-phosphate dehydrogenase activity in skeletal muscle. Respiratory capacity of muscle homogenates was reduced 55%. After 8 days of iron treatment, respiratory capacity, cytochrome c, cytochrome oxidase, and glycerol-3-phosphate dehydrogenase had returned 50% toward normal. Maximum O2 uptake of contracting hindlimb muscles averaged 8.5 mumol O2.min-1.g-1 in control, 4.3 mumol O2.min-1.g-1 in iron-deficient, and 6.2 mumol O2.min-1.g-1 in the 8-day-iron-repleted rats. Muscle fatigue during 10 min of stimulation was greater in the iron-deficient group. Lactate concentration in red muscle was higher in iron-deficient than in control rats after stimulation. The muscle fatigue and lactate responses returned 50% toward normal during 8 days of iron treatment. We conclude that iron deficiency results in a decrease in skeletal muscle capacity for aerobic metabolism and, by this mechanism, increases susceptibility to fatigue.
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PMID:Physiological and biochemical effects of iron deficiency on rat skeletal muscle. 626 4

We present two unrelated patients, a boy and a girl, with a progressive neurologic disorder, characterized by psychomotor retardation, seizures and paresis, the illness being exacerbated during stressful periods. Lactate levels in serum and cerebrospinal fluid were elevated in both patients. Histopathologic studies of muscle tissue revealed mitochondrial abnormalities in the boy; in the girl, slight neuronal degeneration was observed. A cerebral biopsy in the girl showed abnormalities compatible with progressive poliodystrophy. Autopsy in the boy demonstrated progressive poliodystrophy. Biochemical studies in muscle tissue showed a defect of cytochrome aa3 in both patients, connected with a defect of cytochrome b in the girl. The association of defective pyruvate metabolism and progressive poliodystrophy is discussed.
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PMID:Progressive poliodystrophy (Alpers' disease) with a defect in cytochrome aa3 in muscle: a report of two unrelated patients. 630 65

For the purpose of describing early chondrogenic metabolic and structural events, measurements were made of oxidative and other enzymatic activities at various stages in the morphologic development of chondrocytes over a period of 18 to 20 days in continuous cell culture. Comparisons were also made between cells grown in 20% O2 and in 35% O2. These cultures exhibited rapid confluence (within 24 hours), early development of cartilaginous nodules by Day 2 to 3 and metachromatic staining of the chondrocyte matrix by Day 3 to 4. Under 35% O2, cell sheets were thicker and there was increased pleomorphism of chondrocyte and fibroblast cell types, with a relative increase of fibroblast components and reduction in chondroblasts and chondrocyte aggregates. Using the von Kossa staining procedure, calcium salt deposition was observed by Day 9. There was no apparent difference in mineralization of cultures grown under the low and high O2 tensions. Under normoxic conditions cytochrome oxidase and malate dehydrogenase (MDH) activities increased rapidly for the first three to four days and then remained essentially constant. Lactate dehydrogenase (LDH) activity increased continuously over the life of the culture. Acid phosphatase increased rapidly until about Day 13 after which it remained constant, whereas alkaline phosphatase showed a bimodal activity profile. Under hyperoxic conditions, cytochrome oxidase, MDH and alkaline phosphatase activity were significantly inhibited. LDH and acid phosphatase activities were markedly inhibited initially but with time showed a degree of recovery.
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PMID:Development of chick limb bud chondrocytes in cell culture: morphologic and oxidative metabolic observations. 701 57

A human pediatric cardiomyocyte cell culture model of chronic cyanosis was used to assess the effects of low oxygen tension on mitochondrial enzyme activity to address the postoperative increase in lactate and decreased ATP in the myocardium and the high incidence of low-output failure with restoration of normal oxygen tension, after technically successful corrective cardiac surgery. Chronically hypoxic cells (PO2 = 40 mmHg for 7 days) exhibited significantly reduced activities for pyruvate dehydrogenase, cytochrome-c oxidase, succinate cytochrome c reductase, succinate dehydrogenase, and citrate synthase. The activity of NADH-cytochrome c reductase was unaffected. Lactate production and the lactate-to-pyruvate ratio were significantly greater in hypoxic cardiomyocytes. Western and Northern analysis demonstrated a decrease in the levels of various mRNA and corresponding polypeptides in hypoxic cells. Thus hypoxia influences mitochondrial metabolism through acute and chronic adaptive mechanisms, reflecting allosteric (posttranscriptional) and transcriptional modulation. Transcriptional downregulation of key mitochondrial enzyme systems can explain the insufficient myocardial aerobic metabolism and low-output failure in children with cyanotic heart disease after cardiac surgery.
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PMID:Myocardial aerobic metabolism is impaired in a cell culture model of cyanotic heart disease. 981 75

Thyroid hormone (TH) is an important regulator of mitochondrial content and activity. As mitochondrial content and properties differ depending on muscle-type, we compared mitochondrial regulation and biogenesis by T3 in slow-twitch oxidative (soleus) and fast-twitch mixed muscle (plantaris). Male Wistar rats were treated for 21 to 27 days with T3 (200 microg/kg/day). Oxidative capacity, regulation of mitochondrial respiration by substrates and phosphate acceptors, and transcription factors were studied. In soleus, T3 treatment increased maximal oxygen consumption (Vmax) and the activities of citrate synthase (CS) and cytochrome oxidase (COX) by 100%, 45%, and 71%, respectively (P < 0.001), whereas in plantaris only Vmax increased, by 39% (P < 0.01). ADP-independent respiration rate was increased in soleus muscle by 216% suggesting mitochondrial uncoupling. Mitochondrial substrate utilization in soleus was also influenced by T3, as were mitochondrial enzymes. Lactate dehydrogenase (LDH) activity was elevated in soleus and plantaris by 63% and 11%, respectively (P < 0.01), and soleus creatine kinase was increased by 48% (P < 0.001). T3 increased the mRNA content of the transcriptional co-activator of mitochondrial genes, PGC-1alpha, and the I and IV COX subunits in soleus. The muscle specific response to thyroid hormones could be explained by a lower content of TH receptors in plantaris than soleus. Moreover, TRalpha mRNA level decreased further after T3 treatment. These results demonstrate that TH has a major effect on mitochondrial content, regulation and coupling in slow oxidative muscle, but to a lesser extent in fast muscle, due to the high expression of TH receptors and PGC-1alpha transcription factor.
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PMID:Differential effects of thyroid hormones on energy metabolism of rat slow- and fast-twitch muscles. 1560 82


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