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)

Activities of delta amino levulinic synthetase (DALS), cytochrome oxidase (E. C. 1.9.3.1.), NADH cytochrome b5 reductase (NADH red.), NADPH cytochrome P450 reductase (NADPH red.), contents of cytochrome P450 (cyt. P450) and cytochrome b5 (cyt. b5), and levels of hemoglobin and hematocrit were studied in three groups of rats: a) malnourished, b) during recovery from malnutrition, and c) controls. During severe protein malnutrition blood levels of hemoglobin and hematocrit were found to be decreased as well as DALS's activity in homogenized bone marrow and liver. The activity of NADH red, and contents of cyt. P.450 and cyt. b5 in hepatic microsomes were also found significantly depressed. The microsomal activity of NADPH red. as well as mitochondrial cytochrome oxidase did not present significant changes, since values obtained in malnourished rats were similar to those found for the control group. While recovering from malnutrition, when rats were fed a casein based diet (10 NDpCalo/o) supplemented with Fe and Cu, the hepatic enzymatic activities, the cytochrome contents of P450 and b5, and hematocrit experienced a spectacular increase, reaching towards the end of the refeeding period values which could be compared to those found in the control group. Nevertheless, DALS' activity in homogenized bone marrow and hemoglobin levels remained low. Results are discussed in relation to depressed activities and contents of enzymes, coenzymes, metabolites and subtrates involved in the hemoglobin synthesis in the rat bone marrow, during recovery from malnutrition.
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PMID:[Activity of delta-aminolevulinic synthetase, cytochrome oxidase and levels of the mixed function oxidase system during experimental protein malnutrition. Response to re-alimentation]. 22 23

A 42-year-old woman had a 10-year history of external ophthalmoplegia, malabsorption resulting in chronic malnutrition, muscle atrophy and polyneuropathy. Computer tomography revealed hypodensity of her cerebral white matter. A metabolic disturbance consisted of lactic acidosis after moderate glucose loads with increased excretion of hydroxybutyric and fumaric acids. Post-mortem studies revealed gastrointestinal scleroderma as the morphological manifestation of her malabsorption syndrome, ocular and skeletal myopathy with ragged red fibers, peripheral neuropathy, vascular abnormalities of meningeal and peripheral nerve vessels. Biochemical examination of the liver and muscle tissues revealed a partial defect of cytochrome-c-oxidase (complex IV of the respiratory chain). This mitochondrial multisystem disorder may represent a separate entity to be classified between the spectrum of myoencephalopathies and oculo-gastrointestinal muscular dystrophy.
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PMID:Myo-, neuro-, gastrointestinal encephalopathy (MNGIE syndrome) due to partial deficiency of cytochrome-c-oxidase. A new mitochondrial multisystem disorder. 282 22

Effects of changes in dietary protein have been investigated on three mitochondrial enzymes, succinate dehydrogenase, isocitrate dehydrogenase and cytochrome oxidase. Weanling rats (21 days old) were fed for 30 days on (a) a commercially produced diet (CPD) containing 21.0% dietary protein and (b) a low protein-high carbohydrate diet (LPD) containing 3.47% dietary protein. Signs of protein-energy malnutrition developed in the animals having the low protein diet. The mitochondrial enzymes were assayed. Some of the experimental rats were repleted by feeding them on a protein-rich diet for 3 weeks, and the same mitochondrial enzymes were assayed. The activity of mitochondrial cytochrome oxidase, which fell to 24% of the control values during the period of deficiency, rose to 91% of the values for control rats during rehabilitation. The activities of succinate dehydrogenase and NAD+-isocitrate dehydrogenase fell to 75 and 73% of the control values, respectively, during depletion and rose to 83 and 88% during repletion in line with the general rate of recovery of the malnourished rats as reflected by the changes in the body weights during repletion. These results show that mitochondrial cytochrome oxidase is very sensitive to changes in dietary protein. Its activity drops sharply with reduction in dietary protein intake and rises rapidly, outstripping the rate of general recovery on reverting to a protein-rich diet.
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PMID:Cytochrome oxidase status in protein-energy-deficient rats. 300 81

Cyanide is a chemical widely used in industry, and is a major environmental pollutant. Its toxicity is caused by inhibition of cytochrome oxidase resulting in histotoxic hypoxia. The effect of sublethal doses of cyanide on memory and hippocampal neurotransmitters was studied in male Wistar strain albino rats. Cyanide reduced the memory along with reduction in the levels of dopamine and 5-hydroxytryptamine in the hippocampus. Pre-existing malnutrition in the animals exaggerated these effects.
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PMID:Effect of chronic cyanide intoxication on memory in albino rats. 1068 13

Copper plays an essential role as a micronutrient. Deficiency of this element (hypocuprosis) in experimental and domestic animals has a severe impact on growth as well as on reproduction. The occurrence of lesions during hypocuprosis is correlated with the depletion of an enzymatic group in which copper takes part. The aim of this work was to analyse chromosomal aberrations in Aberdeen Angus cows of the province of Buenos Aires in relation with the Cu plasma levels. Short term lymphocyte cultures were made from samples obtained from four groups of animals: two groups with normal levels of copper in plasma and two groups with severe hypocupremia. This analysis showed a significant increase of the frequency of chromosomal aberrations (p<0.001) in the hypocupremic groups in relation with control groups. Finally, the Spearman correlation analysis showed a significant negative association (p<0.05) between copper levels and the yield of chromosomal aberrations. The increase of the frequencies of chromosomal aberrations found in the hypocupremic groups could be explained by the higher oxidative stress suffered by these animals. A lower catalytic activity of enzymes such as Cu/Zn superoxide dismutase (Cu/Zn-SOD) and cytochrome-c oxidase could increase the intracellular production of active oxygen species (O(2)(-), H(2)O(2) and OH(o)) with the consequent clastogenic effects.
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PMID:Clastogenic effect of copper deficiency in cattle. 1075 25

This study aimed at investigating the neural substrates of spatial and non-spatial Behavioural components of exploration to novelty by a neurogenetic approach. Thus, functional imaging and Behavioural analysis were carried out in the Naples High-Excitability (NHE) rats, a model of hyperactivity and attention-deficit. Quantitative cytochrome oxidase (C.O.) histochemistry was used to measure the basal metabolic capacity of different forebrain structures. In parallel experiments, exploration in an 8-arm radial maze (Olton-maze) with extra-maze cues was used to measure attentional, motivational and spatial components of Behaviour after feeding rats' ad-libitum or at a reduced diet. Functional imaging analysis: brains from naive rats were stained for quantitative C.O. histochemistry along with standards. NHE rats showed lower C.O. activity in perirhinal and posterior-parietal cortex (all layers) and cortical amygdala, and greater activity in entorhinal cortex (superficial layers). The outer granular cell layer of the dentate gyrus had greater activity in NHE. Behavioural analysis: at low and high motivational level, maze exploration was reinforced during shaping throughout and then only a single arm. The Behaviour was monitored by a CCD camera and videotaped. (i) There was no line difference in working memory during non reinforced maze exploration, independent of the motivational level; (ii) during shaping with all baited arms, there was no line difference in working memory, but NHE rats showed a very low or lower food consumption at low and high motivational level, respectively; (iii) rats showed a higher working memory in finding the single baited arm at high motivational level; (iv) NHE rats paid little attention towards reinforcement upon visiting the baited arm only at low motivational level. Thus, Behavioural and functional neuroimaging analysis suggests the neural substrates of spatial and non-spatial components of exploration to be underlined by different network operations in the neocortical and limbic cortices in the NHE rat lines. Therefore, they appear as an useful tool to the understanding of Attention-Deficit Hyperactivity Disorder (ADHD) in children.
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PMID:Impaired metabolic capacity in the perirhinal and posterior parietal cortex lead to dissociation between attentional, motivational and spatial components of exploration in the Naples High-Excitability rat. 1186 29

Cellular aging is associated with dysfunction of the mitochondrial respiration chain. Deficiency of mitochondrial cytochrome c oxidase (complex IV) plays a critical role in aging-induced mitochondrial dysfunction. We investigated whether in vitro cellular aging causes the downregulation of complex IV activity and gene expression using senescent (passage 45) and young (passage 3) pulmonary artery endothelial cells (PAEC). In senescent PAEC, the catalytic activity of complex IV decreased 84%, compared to that in young cells. Relative protein levels of complex IV subunits I and IV (complex IV S1 and S4) in senescent cells decreased 91%, compared to those in young cells. This suggests that lack of complex IV S1 and S4 in senescent cells may contribute to the deficiency of complex IV. Total steady state levels of mRNA for complex IV S1 and S4 in senescent cells were decreased to 20% and 18% of those in young cells. The relative rates of mRNA synthesis of complex IV S1 and S4 were decreased 46% and 37% in senescent cells, respectively, compared to young cells. The degradation of complex IV S1 and S4 was increased 76% and 64% in senescent cells, compared to young cells. These data indicate that mitochondrial DNA-encoded subunit I and nuclear DNA-encoded subunit IV of complex IV are downregulated through reduced synthesis and enhanced degradation of their mRNA, which may be responsible for the deficiency of complex IV in replicative senescent PAEC.
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PMID:Down-regulation of mitochondrial cytochrome c oxidase in senescent porcine pulmonary artery endothelial cells. 1229 39

Heme, the major functional form of iron, is synthesized in the mitochondria. Although disturbed heme metabolism causes mitochondrial decay, oxidative stress, and iron accumulation, all of which are hallmarks of ageing, heme has been little studied in nutritional deficiency, in ageing, or age-related disorders such as Alzheimer's disease (AD). Biosynthesis of heme requires Vitamin B(6), riboflavin, biotin, pantothenic acid, and lipoic acid and the minerals zinc, iron, and copper, micronutrients are essential for the production of succinyl-CoA, the precursor for porphyrins, by the TCA (Krebs) cycle. Only a small fraction of the porphyrins synthesized from succinyl-CoA are converted to heme, the rest are excreted out of the body together with the degradation products of heme (e.g. bilirubin). Therefore, the heme biosynthetic pathway causes a net loss of succinyl-CoA from the TCA cycle. The mitochondrial pool of succinyl-CoA may limit heme biosynthesis in deficiencies for micronutrients (e.g. iron or biotin deficiency). Ageing and AD are also associated with hypometabolism, increase in heme oxygenase-1, loss of complex IV, and iron accumulation. Heme is a common denominator for all these changes, suggesting that heme metabolism maybe altered in age-related disorders. Heme can also be a prooxidant: it converts less reactive oxidants to highly reactive free radicals. Free heme has high affinity for different cell structures (protein, membranes, and DNA), triggering site-directed oxidative damage. This review discusses heme metabolism as related to metabolic changes seen in ageing and age-related disorders and highlights the possible role in iron deficiency.
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PMID:Heme, iron, and the mitochondrial decay of ageing. 1523 Dec 38

Deficiency of the frataxin mRNA alters the transcriptome, triggering neuro- and cardiodegeneration in Friedreich's ataxia. We microarrayed murine frataxin-deficient heart tissue, liver tissue and cardiocytes and observed a transcript down-regulation to up-regulation ratio of nearly 2:1 with a mitochondrial localization of transcriptional changes. Combining all mouse and human microarray data for frataxin-deficient cells and tissues, the most consistently decreased transcripts were mitochondrial coproporphyrinogen oxidase (CPOX) of the heme pathway and mature T-cell proliferation 1, a homolog of yeast COX23, which is thought to function as a mitochondrial metallochaperone. Quantitative RT-PCR studies confirmed the significant down-regulation of Isu1, CPOX and ferrochelatase at 10 weeks in mouse hearts. We observed that mutant cells were resistant to aminolevulinate-dependent toxicity, as expected if the heme pathway was inhibited. Consistent with this, we observed increased cellular protoporphyrin IX levels, reduced mitochondrial heme a and heme c levels and reduced activity of cytochrome oxidase, suggesting a defect between protoporphyrin IX and heme a. Fe-chelatase activities were similar in mutants and controls, whereas Zn-chelatase activities were slightly elevated in mutants, supporting the idea of an altered metal-specificity of ferrochelatase. These results suggest that frataxin deficiency causes defects late in the heme pathway. As ataxic symptoms occur in other diseases of heme deficiency, the heme defect we observe in frataxin-deficient cells could be primary to the pathophysiological process.
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PMID:Frataxin deficiency alters heme pathway transcripts and decreases mitochondrial heme metabolites in mammalian cells. 1623 44

The objective of this update is to give an overview of the effects of dietary nutrients on the structure and certain functions of the brain. As any other organ, the brain is elaborated from substances present in the diet (sometimes exclusively, for vitamins, minerals, essential amino-acids and essential fatty acids, including omega- 3 polyunsaturated fatty acids). However, for long it was not fully accepted that food can have an influence on brain structure, and thus on its function, including cognitive and intellectuals. In fact, most micronutrients (vitamins and trace-elements) have been directly evaluated in the setting of cerebral functioning. For instance, to produce energy, the use of glucose by nervous tissue implies the presence of vitamin B1; this vitamin modulates cognitive performance, especially in the elderly. Vitamin B9 preserves brain during its development and memory during ageing. Vitamin B6 is likely to benefit in treating premenstrual depression. Vitamins B6 and B12, among others, are directly involved in the synthesis of some neurotransmitters. Vitamin B12 delays the onset of signs of dementia (and blood abnormalities), provided it is administered in a precise clinical timing window, before the onset of the first symptoms. Supplementation with cobalamin improves cerebral and cognitive functions in the elderly; it frequently improves the functioning of factors related to the frontal lobe, as well as the language function of those with cognitive disorders. Adolescents who have a borderline level of vitamin B12 develop signs of cognitive changes. In the brain, the nerve endings contain the highest concentrations of vitamin C in the human body (after the suprarenal glands). Vitamin D (or certain of its analogues) could be of interest in the prevention of various aspects of neurodegenerative or neuroimmune diseases. Among the various vitamin E components (tocopherols and tocotrienols), only alpha-tocopherol is actively uptaken by the brain and is directly involved in nervous membranes protection. Even vitamin K has been involved in nervous tissue biochemistry. Iron is necessary to ensure oxygenation and to produce energy in the cerebral parenchyma (via cytochrome oxidase), and for the synthesis of neurotransmitters and myelin; iron deficiency is found in children with attention-deficit/hyperactivity disorder. Iron concentrations in the umbilical artery are critical during the development of the foetus, and in relation with the IQ in the child; infantile anaemia with its associated iron deficiency is linked to perturbation of the development of cognitive functions. Iron deficiency anaemia is common, particularly in women, and is associated, for instance, with apathy, depression and rapid fatigue when exercising. Lithium importance, at least in psychiatry, is known for a long time. Magnesium plays important roles in all the major metabolisms: in oxidation-reduction and in ionic regulation, among others. Zinc participates among others in the perception of taste. An unbalanced copper metabolism homeostasis (due to dietary deficiency) could be linked to Alzheimer disease. The iodine provided by the thyroid hormone ensures the energy metabolism of the cerebral cells; the dietary reduction of iodine during pregnancy induces severe cerebral dysfunction, actually leading to cretinism. Among many mechanisms, manganese, copper, and zinc participate in enzymatic mechanisms that protect against free radicals, toxic derivatives of oxygen. More specifically, the full genetic potential of the child for physical growth ad mental development may be compromised due to deficiency (even subclinical) of micronutrients. Children and adolescents with poor nutritional status are exposed to alterations of mental and behavioural functions that can be corrected by dietary measures, but only to certain extend. Indeed, nutrient composition and meal pattern can exert either immediate or long-term effects, beneficial or adverse. Brain diseases during aging can also be due to failure for protective mechanism, due to dietary deficiencies, for instance in anti-oxidants and nutrients (trace elements, vitamins, non essential micronutrients such as polyphenols) related with protection against free radicals. Macronutrients are presented in the accompanying paper.
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PMID:Effects of nutrients (in food) on the structure and function of the nervous system: update on dietary requirements for brain. Part 1: micronutrients. 1706 9


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