Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “CYTOCHROME OXIDASE”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 451 records · Page 25Linked to original sources
PubMed1987

[Criteria for assessing the adequacy of a hypotensive effect by data on the lactate dehydrogenase and cytochrome oxidase isoenzyme spectra of patients with different forms of arterial hypertension].

A study of associations between lactate dehydrogenase and cytochrome oxidase isoenzymes and total cytochrome oxidase activity, on the one hand, and the type of arterial hypertension, the magnitude of blood pressure and its response to treatment, on the other, was carried out in 143 patients with varying stages of essential hypertension and in renal hypertension. The examined parameters were found to be valuable indicators of adequate hypotensive effect and an optimum BP fall. A 20-24% BP drop below the baseline is optimal for patients with renal hypertension. A 30% BP drop is acceptable for patients with stable essential hypertension. Attaining normal BP level is acceptable and desirable for cases of labile essential hypertension.

Antihypertensive Agents↗
PubMedDate not supplied

Cytochrome oxidase activity and confocal laser scanning microscopic analysis of the hamster submandibular gland using microwave irradiated fixation.

Submandibular glands of the hamster were irradiated in 2% paraformaldehyde (pFA)-0.5% pure glutaraldehyde (PGA) with a microwave (MW) processor at temperatures of 10 degrees and 37 degrees C. Electron microscopy showed that cytochrome oxidase activity was taking place in the mitochondrial intermembrane-intracristal space of the granular duct cell when the temperature of the MW-irradiated fixatives was at 10 degrees C. However, a decrease of this activity was observed when we took care to keep the temperature of the MW-irradiated fixatives at 37 degrees C. The distinct reduction of cytochrome oxidase activity allowed by MW irradiation seems to be due the thermal affects of fixatives. Of course, the possibility cannot be excluded that MW irradiation caused other undetectable membrane damage. Then, we used confocal laser scanning microscopy for the preservation check of the mitochondrial membrane for cytochemistry with MW-irradiated fixation. The fluorescence of rhodamine 123 was observed in the inner spaces of the mitochondria at temperatures of 10 degrees and 37 degrees C. When the same tissues were fixed with 2% pFA using an MW processor as the sole fixative at 10 degrees C, no mitochondrial fluorescence was observed. Cytochrome oxidase activity, by contrast, could be seen in the mitochondrial intermembrane-intracristal spaces in the same condition. Formaldehyde is not the best aldehyde for the purpose of ultrastructural preservation. On the other hand, light and electron microscopy showed that the endogenous peroxidase activity was localized in the nuclear envelope, endoplasmic reticulum, secretory granules, and Golgi apparatus of the hamster submandibular gland using 2% pFA-0.5% PGA fixative with and without MW irradiations at temperatures of 10 degrees and 37 degrees C. Some of the same cells were fixed with only 2% pFA under MW irradiation at 10 degrees C; however, marked diffuseness of the peroxidase activity was observed. Therefore, these results indicated that cytochrome oxidase activity was sensitive to heat with MW-irradiated fixation. Peroxidase activity was very resistant to heat with MW-irradiated fixation but not with pFA solo fixation, therefore, PGA had to be used.

Animals↗
PubMed1994

Modular organization of human extrastriate visual cortex: evidence from cytochrome oxidase pattern in normal and macular degeneration cases.

The human extrastriate occipital cortex contains several visual areas that are probably analogues of macaque areas V2, V3, VP, V4 and V5. Tracing of callosal connections has led to the anatomical identification of these areas and to the characterization of some of them by cyto- and myeloarchitecture (Clarke and Miklossy, 1990). The pattern of cytochrome oxidase activity in these visual areas is now described in a normal case and in a case of age-related bilateral macular degeneration. In normal cortex, the laminar distribution of cytochrome oxidase activity was similar in V2, V3, VP, V4 and V5; a prominent dark band covered most of layers III and IV, and its upper and lower limits were gradual. In V2, V3, V4 and V5 but not VP, layer II tended to be darker than the infragranular layers. The overall intensity of the staining varied between areas: VP was very light, V2, V3 and V4 were darker, and V5 was very dark. A different, two-band pattern of cytochrome oxidase activity was found in a restricted region of the posterosuperior precuneus. The bilateral age-related macular degeneration had led to a great loss of ganglion cells in the central, but not in the peripheral retinae. The central representation in the lateral geniculate nuclei showed abnormally weak staining for cytochrome oxidase, particularly in the parvocellular layers. In the cortex, the contrast between lightly and darkly stained regions was greater than in the normal case. In particular, V5 was very heavily stained, and in V1 and V2 there were two different types of dark stripes that may represent compartments driven predominantly by the magnocellular system.

Aged↗
PubMed1995

Changes in regional cytochrome oxidase activity in the fetal, newborn and adult ovine brainstem.

Metabolic activity of specific brain regions (e.g. brainstem respiratory centers) may increase during the physiologic adaptations at birth. Since regional activity of cytochrome oxidase is correlated with the level of oxidative metabolism, cytochrome oxidase histochemistry was used to investigate whether there are sustained changes in metabolic activity within specific nuclei of the ovine brainstem during the perinatal period and whether further changes occur in the adult. Histochemistry was performed on 10-microns-thick frozen sections of the perinatal (130 d fetus, 140 d fetus, 8 h newborn and 10 d newborn) and adult ovine brainstem (n = 3 at each age). Computer-assisted image analysis was performed on 20 brainstem regions. A general decreasing trend, interrupted by a tendency for a transient increase at 8 h after birth was observed in most regions analyzed. Statistically significant decreases (P < 0.05) in cytochrome oxidase levels between the perinatal age groups and the adult were found in 7 brainstem nuclei studied: ambiguus, cuneate, inferior olivary, reticularis lateralis, spinal trigeminal, parabrachial and superior olivary nuclei. Within the perinatal period, the nucleus gracilis was the only region to show statistically significant decreases in 140 d fetus and 8 h newborns in all nuclei analyzed, but this change was not statistically significant (P > 0.1). These results indicate that the dramatic changes in physiology and environment at birth do not result in a significant change in the metabolic capacity of brainstem nuclei in the immediate perinatal period. However, more gradual developmental changes are observed in specific brainstem nuclei suggesting a decrease in neuronal activity occurs in these areas during development in the sheep.

Aging↗
PubMed1980

Biochemical effects of carbon monoxide poisoning in rat brain with special reference to blood carboxyhemoglobin and cerebral cytochrome oxidase activity.

Male Wistar rats exposed to 1000 ppm carbon monoxide for 3 h showed a rapid removal of carbon monoxide from the blood, and a cerebral cytochrome oxidase activity within the control range immediately after the end of the exposure. The cytochrome oxidase activity decreased while carboxyhemoglobin concentration diminished during the reoxygenation period. The effect might have been caused through a loss of mitochondria by increased lipid peroxidation as cerebral glutathione concentration decreased and lysosomal acid proteinase activity increased in glial cell fractions. The present results seem to indicate that the cerebral cytochrome oxidase may not be specifically inhibited in non-lethal carbon monoxide poisoning despite its proven interactions in vitro.

Animals↗
PubMed1988

Cytochrome oxidase activity in brown fat varies with reproductive response and use of torpor in deer mice.

Reproductive responses and thermogenic properties of brown adipose tissue (BAT) were evaluated in individuals from an outbred population of deer mice (Peromyscus maniculatus nebrascensis) after 10 weeks exposure to short photoperiod (8:16 light:dark) and cold ambient temperature (2 degrees C). Deer mice populations are composed of phenotypes that differ in their reproductive response to environmental cues. These phenotypes also differ in body temperature regulation as indicated by their use of daily torpor. By comparing BAT responses among individuals of different phenotypes, we were able to assess the association between environmentally induced changes in reproduction and metabolism. Short/cold days caused increased proliferation of BAT and higher cytochrome oxidase activity. However, the magnitude of these changes varied with reproductive phenotype and use of daily torpor. BAT weight in short/cold day exposed males with normal sized testes more than doubled while total cytochrome oxidase activity increased by 30% as compared to controls. In contrast, short/cold day exposed deer mice with atrophic testes that employed daily torpor exhibited a 64% increase in BAT weight and 100% increase in total cytochrome oxidase activity, compared to control mice. Cytochrome oxidase activity in nontorpid deer mice with atrophic testes was intermediate to these two groups. Our results demonstrate a response of BAT to short/cold days that varies with individual reproductive response. This finding suggests that there exists a common integrative mechanism for temperature and photoperiod to regulate both seasonal reproductive and metabolic adjustments.

Adipose Tissue, Brown↗
PubMed1987

Studies on the oligomeric state of isolated cytochrome oxidase using cross-linking reagents.

(1) Sucrose gradient centrifugation of cytochrome oxidase in the presence of Triton X-100 gave one slowly sedimenting green band. After cross-linking with dithiobis(succinimidylpropionate) (DSP), two green bands were observed, one sedimenting like the control and the other one more rapidly. Only the slowly sedimenting band was observed if the cross-linker was cleaved by dithiothreitol before centrifugation. (2) The rapidly sedimenting band in the Triton-containing sucrose gradient is probably the internally cross-linked dimer of cytochrome oxidase; the one sedimenting slowly is the monomeric enzyme. (3) Cross-linking with DSP after monomerization yields a small fraction of internally cross-linked dimers in addition to the internally cross-linked monomers. Under similar conditions, but using the shorter cross-linker disuccinimidyl tartarate (DST), no dimers are detected. (4) Both DSP and DST cross-link the dimeric enzyme so that it could no longer be monomerized by centrifugation in Triton, unless the cross-link is cleaved. (5) Polypeptide analysis using two-dimensional gel electrophoresis of cross-linked dimers and monomers suggest that subunit VIb is involved in intermonomeric cross-linking of dimeric enzyme by DSP.

Animals↗
PubMed1979

[Activity of delta-aminolevulinic synthetase, cytochrome oxidase and levels of the mixed function oxidase system during experimental protein malnutrition. Response to re-alimentation].

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.

5-Aminolevulinate Synthetase↗
PubMed1986

Depletion of brain mitochondria cytochrome oxidase in the mottled mouse mutant.

The mouse mutant Mobr is an animal model of Menkes kinky hair syndrome with a similar defect in copper utilization. The copper-dependent enzyme, cytochrome oxidase from the brain, liver, and heart mitochondria was examined. The brain and heart from Mobr/y had significantly less cytochrome alpha + alpha 3 than normal animals' when the cytochrome absorption spectra of tissue samples from animals 11 to 13 days of age were analyzed. Liver cytochrome was not significantly different. When brain mitochondrial cytochrome oxidase spectrograms from animals of different ages were examined, a major change was found to occur during the 2nd week of life. When cytochrome oxidase activity from brain mitochondria was measured, assaying the rate of oxidation of cytochrome c, the results were similar to those from spectrogram analysis.

Animals↗
PubMed2000

Cytochrome oxidase activity in rat retinal ganglion cells during postnatal development.

In this study, the metabolic activity of rat retinal ganglion cells during postnatal development has been examined in vivo using cytochrome oxidase histochemistry. The intensity of staining was measured by optical densitometry. The activity of cytochrome oxidase in retinal ganglion cells progressively increased from postnatal day 0 (P0) and reached a peak during the second week of postnatal development (P10-P14) and declined thereafter. Our data show that the increased levels of cytochrome oxidase seen in developing retinal ganglion cells occur at the same time, when neuronal maturity and synaptogenesis reach their peaks.

Aging↗
PubMed1995

Structure and function of a molecular machine: cytochrome c oxidase.

Cytochrome c is responsible for over 90% of the dioxygen consumption in the living cell and contributes to the build-up of a proton electrochemical gradient derived by the vectorial transfer of electrons between cytochrome c and molecular oxygen. The metal ions found in cytochrome oxidases play a crucial role in these processes and have been extensively studied. In this review we present and discuss some of the relevant spectroscopic and kinetic properties of the prosthetic groups of cytochrome c oxidase.

Animals↗
PubMed1983

Cytochrome oxidase activity of mitochondria from ischemic and reperfused myocardium.

Polarographic measurements show that activity of cytochrome oxidase (CO), assayed as ascorbate plus TMPD oxidase, is decreased in the mitochondria (M) from postischemic areas of rabbit heart 1, 6, and 9 days after temporary (1-hr) coronary artery occlusion (CAO). This effect is observable only in the absence of added cytochrome c. Cytochrome oxidase activity in the cytochrome c-containing medium was not different from the control level. Levels of cytochromes c + c1 and a were substantially lower in tissue from postischemic areas and elevated in the intact tissue 1 and 6 days after temporary CAO as compared with control hearts. Stoichiometry of the cytochromes was not changed. After 1 or 4 hr of permanent CAO, CO activity (plus cytochrome c) of ischemic M was equal to that of M from intact area; CO activity (with or without cytochrome c) was reduced after 0.5 and 1 hr but elevated after 3 or 4 hr of in vitro ischemia as compared with control. The changes of CO activity in infarcted human heart M were similar to those in rabbits after temporary CAO; CO activity was restored after addition of cytochrome c. The data suggest that leakage of cytochrome c occurs during isolation of M and is more pronounced in ischemia-damaged M.

Animals↗
PubMed1988

Nucleotide sequence of the gene coding for cytochrome oxidase subunit I from the thermophilic bacterium PS3.

The gene coding for cytochrome oxidase subunit I (COI) was isolated from a genomic DNA library of the thermophilic bacterium PS3 and sequenced. The N-terminal of the COI protein was also sequenced to verify the initiation site of the reading frame. The deduced amino acid sequence of COI protein is composed of 536 amino acid residues and its molecular mass is 59,510. The protein is clearly homologous to the corresponding subunit in the mitochondrial cytochrome oxidase and similarly appears to have 12 trans-membrane segments. The proposed ligands to two hemes (cytochrome aa3) and a copper atom (CuB) in this protein (Holm et al. (1987) EMBO J. 6, 2819-2823) are conserved in the sequence.

Amino Acid Sequence↗
PubMed2001

Sulfite oxidation by iron-grown cells of Thiobacillus ferrooxidans at pH 3 possibly involves free radicals, iron, and cytochrome oxidase.

Thiobacillus ferrooxidans cells grown on ferrous iron oxidized sulfite to sulfate at pH 3, possibly by a free radical mechanism involving iron and cytochrome oxidase. A purely chemical system with low concentrations of Fe3+ simulated the T. ferrooxidans system. Metal chelators, ethylenediamine tetraacetic acid (EDTA), 4,5-dihydroxy-1-3-benzene disulfonic acid (Tiron), o-phenanthroline, and 2,2'-dipyridyl, inhibited both sulfite oxidation systems, but the T. ferrooxidans system was inhibited only after the initial brief oxygen consumption. EDTA and Tiron, strong chelators of Fe3+, inhibited the oxidation at lower concentrations than o-phenanthroline and 2,2'-dipyridyl, strong chelators of Fe2+. Inhibition of Fe3+-catalyzed sulfite oxidation by EDTA and Tiron was instant, but the inhibition by o-phenanthroline and dipyridyl was briefly delayed, presumably for the reduction of Fe3+ to Fe2+. Mannitol, a free radical scavenger, inhibited both systems to the same extent. Cyanide and azide inhibited only the T. ferrooxidans system, suggesting a role of cytochrome oxidase. It is proposed that sulfite is oxidized by a free radical mechanism initiated by Fe3+ on the cell surface of T. ferrooxidans. Cytochrome oxidase is possibly involved in the regeneration of Fe3+ from Fe2+ by the normal Fe2+-oxidizing system of T. ferrooxidans.

Acids↗
PubMed1989

Cytochrome oxidase activity in retinas transplanted to the brainstem in rats.

Fetal retinas were transplanted to the brainstem of newborn rats and their morphological features were examined using the cytochrome oxidase histochemical method at maturity. The results showed that the inner segments of photoreceptors, outer and inner plexiform layers as well as ganglion cells with large somata were moderately to darkly stained for cytochrome oxidase. This pattern is basically the same as that observed in the normal retina, suggesting that cytochrome oxidase can be used not only for revealing spatial but also functional organization of retinal transplants.

Animals↗
PubMed1993

Effect of indomethacin on cerebral oxidized cytochrome oxidase in preterm infants.

To determine the effect of i.v. indomethacin on cerebral intracellular oxygenation, as judged by changes in the concentration of oxidized cytochrome oxidase, studies were performed using near-infrared spectroscopy on 15 infants of 23 to 29 wk gestation, aged 8 to 30 d, who required the drug for closure of a patent ductus arteriosus. Indomethacin caused significant (p < 0.01) falls in cerebral blood flow, oxygen delivery, and blood volume and its reactivity to changes in arterial carbon dioxide tension, as previously reported. In 11 of the 15 infants, significant (p < 0.01) falls of 0.18 to 0.92 mumol.L-1 in the concentration of oxidized cytochrome oxidase were observed. Parallel experiments on synaptosomes derived from rat brain showed that indomethacin was most unlikely to have had a direct effect on mitochondrial respiration. These results are consistent with the hypothesis that the observed falls in the concentration of oxidized cytochrome oxidase resulted from hemodynamic perturbations that reduced cerebral intracellular oxygenation.

Animals↗
PubMed1984

The distribution of hexokinase compared to cytochrome oxidase and acetylcholinesterase in the somatosensory cortex and the superior colliculus of the rat.

The distribution of hexokinase, a general glycolytic enzyme, was compared to that of cytochrome oxidase and acetylcholinesterase (AChE) in the somatosensory cortex and the superior colliculus of the rat. The vibrissal barrel fields of the adult rat contain high hexokinase and cytochrome oxidase activity and low AChE activity. In the superior colliculus, hexokinase activity was highest in cell layers and discrete foci of intense activity were observed in the deep grey layer. This distribution was different from that of both cytochrome oxidase and AChE in this structure.

Acetylcholinesterase↗
PubMed1969

Cytochrome oxidase deficiency in Wilson's disease: a suggested ceruloplasmin function.

The hypothesis is advanced that ceruloplasmin functions in enzymatic transfer of copper to copper-containing enzymes, such as cytochrome oxidase. To test this hypothesis, leucocytes from Wilson's disease patients, heterozygous carriers, and normal subjects were assayed for cytochrome-oxidase activity. The data reported here show markedly reduced levels of activity in Wilson's disease cases and moderate reductions in heterozygous individuals relative to normal controls. These observations and a close correlation between the level of cytochrome-oxidase activity in the leucocytes and ceruloplasmin in the serum tend to support the hypothesis.

Adolescent↗