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)

In the subcommissural organ (SCO) of the guinea pig, rat, golden hamster, and mouse the activity and distribution of enzymes related to the energy-supplying metabolism and of some marker enzymes of different cell organelles have been investigated by means of mostly modified histochemical methods. The results were compared with findings in the ciliated ependyma of the ventricular wall and with those in the ependyma of the choroid plexus of the third ventricle. In the ependymal part of the SCO only a moderate activity of hexokinase is observed in its specialized columnar cells whereas a high activity is present both in the ciliated ependyma and the choroid plexus. - The staining pattern of glucose-6-phosphatase is similar to that of hexokinase but this enzyme is found is the SCO only. - Likewise hexokinase, glycogen granules and enzymes related to glycogen metabolism (phosphoglucomutase, uridine-diphosphoglucose pyrophosphorylase, glycogen synthetase and phosphorylase) are regularly found most numerous and active in the nuclear and supra-nuclear area of the ependymal part. These enzymes are less active in both the other ependymal regions. - Uridine-diphosphoglucose dehydrogenase could not be demonstrated in the SCO. The NADP-linked enzymes of the pentose phosphate shunt, glucose-6-phosphate and 6-phosphogluconate dehydrogenase, show a moderate activity which decreases also from the nuclear towards the apical area of the ependymal cells of the SCO. Enzymes of the glycolytic pathway, such as glucosephosphate isomerase, fructose-6-phosphate kinase, fructose-I,6-diphosphate aldolase, glyceraldehyde-3-phosphate and lactate dehydrogenase, are highly active in the SCO and are located mainly in the supranuclear area, too. Fructose-1,6-diphosphatase could not be demonstrated thus indicating that in the SCO the pathway is most probably only glycolytic but not gluconeogenetic. Compared to the ependyma of the ventricular wall and of the choroid plexus, in the SCO the M type subunits of lactate dehydrogenase predominate. Glycolytic enzymes are also very active in the choroid plexus but less in the ciliated ependyma. Compared to the ciliated ependyma and especially to the ependyma of the choroid plexus, the activities of enzymes which are only present in mitochondria (NAD-linked isocitrate dehydrogenase, succinate dehydrogenase, NAD-linked malate dehydrogenase after preextraction, cytochrome oxidase, 3-hydroxybutyrate and glycerolphosphate and glutamate dehydrogenase) are relatively low. Mitochondria are accumulated near the superior pole of the nuclei as well as in the most apical part of the ependymal cells. - The staining pattern of NADP-linked isocitrate and malate dehydrogenase as well as of NADH dehydrogenase suggests that these enzymes are localized both in and out of mitochondria. The extramitochondrial activity of the first two enzymes might be localized in the cytosol. The extramitochondrial activity of NADH dehydrogenase might be localized in the endoplasmic reticulum...
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PMID:Enzymatic organization of the subcommissural organ. 123 49

Electron microscopic enzyme cytochemical reactions of Entamoeba histolytica trophozoite showed that acid phosphatase (ACP) and cytidine monophosphatase (CMPase) were located in the lysosomes. The lysosome containing enzymes were distributed in the endoplasm and beneath the plasmalemma, and the releasing enzymes by lysosomes excreted outside of the plasmalemma and caused the injury to host cells. The cytochemical positive reactions of catalase and glucose-6-phosphatase (G-6-Pase) showed that E. histolytica contains microbodies and endoplasmic reticulum. The reactive products of peroxidase (POase) were seen in the lysosome-like structure. The reactions of cytochrome oxidase (COase) and succinate dehydrogenase (SDH) were both negative, indicating that E. histolytica lacked mitochondria. The reactions of thiamine pyrophosphatase (TPPase) and nicotinamide adenine dinucleotide phosphatase (NADPase) were both negative, indicating that E. histolytica lacked Golgi body. The reactions of Na(+)-K(+)-ATPase were located on plasmalemma.
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PMID:[Electron microscopic enzyme cytochemistry of Entamoeba histolytica trophozoite]. 133 24

HepG2 cells were cultured in the presence of different concentrations of cyclosporin A (CsA) or Nva2-cyclosporin (Nva2-Cs) for up to 20 days. At a low concentration (2 micrograms/ml) of CsA or Nva2-Cs, the [3H]thymidine incorporation into DNA and the rate of incorporation of [3H]leucine into total protein decreased by 20-25%. Concentrations of 10 micrograms/ml resulted in a 70% reduction of the [3H]thymidine incorporation in comparison with controls. Low concentrations of CsA resulted in mitochondria in the condensed state together with autophagosomes, large vacuoles, and elevated numbers of coated vesicles, as shown by electron microscopy. Low concentrations of Nva2-Cs resulted in swollen mitochondria, increased autophagocytosis, and increased numbers of intermediate filaments and microtubules. Higher doses of these substances (5 micrograms/ml) caused disarrangement of mitochondrial cristae, vesiculation of the endoplasmic reticulum, an elevated number of free polysomes, and accelerated autophagocytosis. Labeling of phospholipids and triglycerides with [3H]glycerol and of cholesterol and dolichol with [3H]acetate was decreased after exposure of HepG2 cells to CsA, or, in particular, Nva2-Cs. Phospholipids secreted from the cells into the medium exhibited an increased level of labeling, but the specific radioactivity of the neutral lipids in the medium was significantly decreased. Treatment of HepG2 cells with either CsA or Nva2-Cs doubled the mitochondrial cytochrome oxidase and carnitine acetyl-transferase, as well as microsomal NADPH-cytochrome c reductase activities. Such treatment also increased the cyanide-insensitive beta-oxidation of fatty acids in peroxisomes, as well as cytoplasmic DT-diaphorase and glutathione transferase activities. Prolonged treatment of the cells with CsA did not result in any cumulative effect. HepG2 cells appear to be suitable for studying the effects of cyclosporins on cellular structure and metabolism and in this system the two drugs studied here exhibited similar effects.
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PMID:Modulation of metabolism in HepG2 cells upon treatment with cyclosporin A and Nva2-cyclosporin. 164 68

Exposure of rats to magnetic fields of 10(-3) and 10(-2) T for 1 hr daily generated structural changes in hepatocytes mitochondria, endoplasmic reticulum, and ribosomes. Simultaneously there was an increase in the activities of the mitochrondrial respiratory enzymes: NADH dehydrogenase, succinic dehydrogenase, and cytochrome oxidase. The extent of the changes in liver cell properties following exposure depend on the duration of exposure to and the strength of the applied magnetic fields. Ultrastructural studies did not reveal any changes in external membranes of hepatocytes or in the membranes of cell nuclei. An increase in the amount of glycogen in hepatocytes of rats exposed to both 10(-3) and 10(-2) T was noted. The high level of cortisol in serum of exposed rats suggests that magnetic field may be a stress generating factor.
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PMID:Structural and functional changes in organelles of liver cells in rats exposed to magnetic fields. 165 Dec 25

The fast axonal transport of [3H]proline-labeled proteins and [3H]fucose-labeled glycoproteins delivered to the dorsal lateral geniculate nucleus in the developing rat optic nerve was investigated during tetrodotoxin-induced monocular impulse blockade. Repeated intraocular injections of various dosages of tetrodotoxin or citrate buffer vehicle were made every two days in rats aged 5-21 days postnatal, and the accumulation of rapidly transported radioactivity in the lateral geniculate nucleus measured between three and twelve hours post-injection at each age. The effectiveness of prolonged tetrodotoxin treatment was monitored by loss of the pupillary light reflex and the level of cytochrome oxidase activity in the contralateral superior colliculus and dorsal lateral geniculate nucleus. Numbers of optic axons proximal to the chiasm and the frequency of retinal ganglion cells per unit distance from the optic disc were examined for signs of tetrodotoxin-induced degeneration of the retinofugal pathway. Tetrodotoxin-treatment reduced the amount of fucosyl glycoproteins, but not proline-labeled proteins, axonally transported to the lateral geniculate nucleus during the first three weeks of postnatal development. Other studies indicated that tetrodotoxin significantly reduced the incorporation of [3H]fucose into retinal proteins indicating that the reduction in transport was probably due to a decrease in precursor incorporation into retinal ganglion cells. Electron microscopy of ganglion cells at 21 days revealed dilated and vacuolated Golgi cisternae associated with tetrodotoxin treatment, suggesting that tetrodotoxin may alter fucose metabolism by secondarily disrupting Golgi organization. Other protein synthetic machinery in these cells, including ribosomes and rough endoplasmic reticulum, appeared normal throughout tetrodotoxin treatment. These data indicate that Na+-dependent optic impulse activity may be indirectly related to the axonal transport of glycoproteins during early postnatal development by mediating the incorporation of precursor into glycoproteins at the Golgi apparatus and their subsequent entrance into the fast transport system.
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PMID:The effect of intraocular injection of tetrodotoxin on fast axonal transport of [3H]proline- and [3H]fucose-labeled materials in the developing rat optic nerve. 241 84

Energy-dependent Ca2+ uptake was characterized in vesicles derived from rat submandibular salivary glands. Ca2+ transport was stimulated by submicromolar levels of Ca2+, reached a plateau at 1-20 microM Ca2+ then again increased as the Ca2+ concentration rose to millimolar levels. Ruthenium red (2.5 microM) was used to resolve this pattern of uptake into two components: ruthenium red-insensitive Ca2+ transport occurs in the presence of the dye, is stimulated by submicromolar Ca2+ concentrations and reaches a maximum steady state at about 1 microM Ca2+. The distribution of ruthenium red-insensitive Ca2+ uptake in membrane subfractions obtained by differential centrifugation is positively (r = 0.717) and significantly (p = 0.001) correlated with the distribution of membrane-bound RNA in the same subfractions. Ca2+ uptake which is abolished by ruthenium red is greatest at millimolar Ca2+ concentrations. Its distribution is positively (r = 0.828) and significantly (p = 0.0001) correlated with the cytochrome-c oxidase activity of the membrane subfractions but is unrelated to the distribution of particulate RNA and is negatively correlated with Na+-K+ ATPase activity. We conclude that vesicles derived from the endoplasmic reticulum of rat submandibular glands actively transport Ca2+ by a ruthenium red-insensitive mechanism which is stimulated at Ca2+ concentrations typical of the cytosol. Membranes derived from mitochondria also sequester Ca2+ but by a mechanism which is inhibited by ruthenium red and which reaches its maximum steady state capacity at relatively high Ca2+ concentrations.
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PMID:Characterization and localization of two forms of active Ca2+ transport in vesicles derived from rat submandibular glands. 242 Apr 66

The cytochemical expression of epidermal peroxidase and cytochrome oxidase activity was recently well documented in normal human skin. We report here its expression in basal and squamous cell carcinomas, actinic keratoses, psoriasis, allergic contact dermatitis, seborrheic keratoses, and autosomal dominant ichthyosis vulgaris. The two enzyme activities were evaluated using the diaminobenzidine method. If present, the two enzymes were always localized in the same organelles as in normal epidermis: endogenous peroxidase in the nuclear envelope and endoplasmic reticulum, and cytochrome oxidase in mitochondria. In basal and squamous carcinomas, actinic keratoses and psoriasis, the keratinocytes lost their peroxidase activity, but maintained their cytochrome oxidase activity. In seborrheic keratoses, allergic contact dermatitis and ichthyosis vulgaris, the cytochrome oxidase activity was greatly reduced or abolished in keratinocytes, Langerhans' cells, and melanocytes, whereas the peroxidase activity was present as in normal epidermis. These results indicate that the two peroxidatic enzymes studied are not interrelated and alternatively suppressed by different cellular dysfunctions.
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PMID:Cytochemical expression of epidermal peroxidase and cytochrome oxidase activities in pathological skin conditions of man. 243 58

We have undertaken the analytical fractionation of epithelial cells from toad urinary bladder, a tissue extensively used to study epithelial transport of ions and water. In an attempt to establish markers for the main subcellular organelles, a number of enzymes were assayed in cell homogenates. The nearly ubiquitous plasma membrane marker 5'-nucleotidase, and the transferases that donate N-acetylglucosaminyl, galactosyl, and sialyl residues to glycoproteins and glycolipids in the Golgi complex were not detectable. Glucose-6-phosphatase activity was low in relation to that of nonspecific phosphatases and, therefore, not suitable for identifying the endoplasmic reticulum. Like the cytosolic enzyme lactate, dehydrogenase, catalase was essentially found in the high-speed supernatant, with a noteworthy part of aminopeptidase (substrate, leucyl-beta-naphthylamide) and NAD glycohydrolase. Other enzymes, including cytochrome c oxidase, acid phosphatase, acid N-acetyl-beta-glucosaminidase, alkaline phosphatase, alkaline phosphodiesterase I, nucleoside diphosphatase (substrate ADP), oligomycin-resistant Mg++-ATPase, and mannosyltransferase (acceptor, dolichylphosphate) were fairly active and largely sedimentable. After differential centrifugation, cytochrome oxidase, acid phosphatase, and acid N-acetyl-beta-glucosaminidase were typically associated with the large granule fraction, whereas the other sedimentable enzymes exhibited a broad distribution profile overlapping the nuclear, large granule, and microsome fractions. Their behavior in density equilibrium centrifugation is examined in a companion paper.
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PMID:Subcellular fractionation of epithelial cells from toad urinary bladder. 1. Assay of marker enzymes and differential centrifugation. 250 71

Young adult rats absorbed 50 p.p.m. Cd2+ added to drinking water. After 6 weeks, 3, 6 and 9 months of treatment, the ultrastructural condition of liver, kidney and muscle was observed by electron microscopy. The choice of these tissues was determined by their differences in the capacity to accumulate Cd2+: the liver is able to concentrate a considerable amount of metal, but redistributes it throughout the entire organism, while the kidney collects it in view of its elimination. Muscle contains the least Cd2+. A general regression in mitochondria cristae accompanied by a vesiculation and a fragmentation of endoplasmic reticulum appeared simultaneously in the three tissues, at as early as 6 weeks of treatment, and extended progressively with its continuation supporting evidence of a general attack of the intracellular membrane systems. Cd2+ stimulation of membrane-degrading enzymes such as phospholipases and proteases was suggested. A concomitant diminution in glycogen stores was noted. Active synthesis of neutral lipids, especially cholesterol esters, took place in liver mitochondria of treated rats in collaboration with rough endoplasmic reticulum, and progressively generated a multiplication of electron-transparent inclusions in cytoplasm. Isolated mitochondria from liver, kidney and muscle of Cd2+-treated rats maintained partial energy coupling, but displayed a rapid early fall in cytochrome oxidase followed by a partial restoration after 6 months of treatment, and a progressively slackening of succinate dehydrogenase. Isolated vesicles of liver mitochondria inner membrane of treated rats behaved as intact mitochondria, indicating changes inside the membrane itself. Addition in vitro of the metal ion to mitochondria and also to inner membrane vesicles isolated from control rats revealed that Cd2+ was able to stop completely succinate dehydrogenase, but was totally ineffective on cytochrome oxidase. Membrane fixation of Cd2+ on the flavoprotein or SH associated with succinate dehydrogenase is proposed. Considering the close parallelism of the extensive depression of microsomal NADPH cytochrome c reductase and the rapid fall in mitochondrial cytochrome oxidase, it is suggested that an indirect inhibition process occurs, through Cd2+-induced diminution of a constituent common to all cytochromes in the cell.
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PMID:Mitochondria alterations in Cd2+-treated rats: general regression of inner membrane cristae and electron transport impairment. 293 99

We have investigated the subcellular localization of the peripheral-type benzodiazepine receptor in rat adrenal gland using the high affinity ligand 3H-labeled 1-(2-chlorophenyl)-N-methyl-(1-methylpropyl)-3-isoquinoline carboxamide ([3H]PK11195). The autoradiographic pattern of [3H]PK11195 binding sites in tissue sections of adrenal gland is similar to the histochemical distribution of the mitochondrial marker enzymes, cytochrome oxidase and monoamine oxidase, which are present in high concentrations only in the cortex. Subcellular fractionation studies of homogenates of adrenal gland indicate that the recovery and enrichment of [3H]PK11195 binding sites in the nuclear, mitochondrial, microsomal, and soluble fractions correlate closely with cytochrome oxidase activity, but not with markers for the nuclei, lysosomes, peroxysomes, endoplasmic reticulum, plasma membrane, or cytoplasm, indicating an association of the peripheral-type benzodiazepine receptor with the mitochondrial compartment. Titration of isolated mitochondria with digitonin results in the simultaneous release of the peripheral-type benzodiazepine receptor and of monoamine oxidase, but not cytochrome oxidase, indicating association of the peripheral-type benzodiazepine receptor with the mitochondrial outer membrane. Scatchard analysis and drug displacement studies of the binding of [3H] PK11195 to intact mitochondria and to the outer membrane-enriched digitonin extract further confirm the localization of the peripheral-type benzodiazepine receptor to the mitochondrial outer membrane.
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PMID:The peripheral-type benzodiazepine receptor. Localization to the mitochondrial outer membrane. 300 Oct 71


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