Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:1.9.3.1 (cytochrome oxidase)
 8,822 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Rat liver endoplasmic reticulum has been separated into four ribosome-containing subfractions, two from rapidly sedimentation endoplasmic reticulum and two from the microsomes, by differential centrifugation and sucrose density centrifugation. Ribosomes from one of the rapidly sedimenting subfractions were extracted by Trion X-100 as a complex with cytochrome P-450, optimally at a detergent protein ratio of 2/1 (w/w). Upon extraction approximately 50% of the cytochrome P-450 in the membrane appeared complex-bound to ribosomes, and, maximally, 6-7 subunit molecules of the cytochrome were attached per ribosome. The specific concentration of cytochrome P-450 on these ribosomes was 2.5-times higher than in the parent membrane. Cytochrome b5, glucose-6-phosphatase, NADPH-cytochrome c reductase, NADH-ferricyanide reductase, cytochrome oxidase and phospholipids were present in small or trace amounts on the ribosomes in relation to cytochrome P-450. Ribosomes extracted from other subfractions contained much less bound cytochrome P-450. Phenobarbital treatment induced an increase in the cytochrome P-450 content that was different for the various subfractions. This increase could not be correlated with changes in the amounts of cytochrome-ribosome complexes released by detergent. We propose that cytochrome P-450 is part of a specific binding site in the membrane for a fraction of the ribosomes attached to the endoplasmic reticulum. The ribosomes may be anchored to cytochrome P-450 via nascent chain proteins.
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PMID:On the involvement of cytochrome P-450 in the binding of ribosomes to a subfraction of rat-liver rapidly sedimenting endoplasmic reticulum. 83 30

The effect of phenobarbital (100 mg/kg i.p.) and 6-aminonicotinamide (6AN) (35 mg/kg i.p.) on enzyme activities related to energy transduction was investigated on the homogenate "in toto", non-synaptic mitochondrial fraction and synaptosomal fraction isolated from different rat brain areas (cerebral cortex, hippocampus, hypothalamus, striatum, and medulla oblongata). 6AN treatment decreased: phosphofructokinase in all the areas tested; lactate dehydrogenase on the homogenate "in toto" in striatum and hypothalamus, and on the synaptosomal fraction in cerebral cortex and corpus striatum; succinate dehydrogenase on non-synaptic mitochondrial fraction in hippocampus and striatum. Finally, aspartate aminotransferase was increased on non-synaptic mitochondrial fraction in striatum and medulla oblongata. Phenobarbital treatment induced an increase of total NADH cytochrome c reductase on mitochondrial fraction in hippocampus and hypothalamus, and a decrease of cytochrome oxidase activity on non-synaptic mitochondrial fraction in hypothalamus and medulla oblongata.
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PMID:Phenobarbital and 6-aminonicotinamide effect on cerebral enzymatic activities related to energy metabolism in different rat brain areas. 303 30

A new approach to high-resolution 2-deoxy-D-glucose (2DG) emulsion-autoradiography which combines improved retention of 2DG labeling, staining with immunohistochemical and other specific markers, and automated data collection and analysis of local silver grain and stain densities is described. The Durham et al. (J. Neurosci. 1:519-526, '81) procedure for fixation of 2DG with periodate-lysine-paraformaldehyde (PLP, McLean and Nakane: J. Histochem. Cytochem. 22:1077-1083, '74) was adapted to increase retained label roughly tenfold. Phenobarbital anesthesia is induced 45 minutes after 2DG injection. Barbiturate anesthesia increases brain glycogen (Nelson et al.: J. Neurochem. 15:1271-1279, '68) and presumably increases the incorporation of intracellular 2DG from 2DG-6P into brain glycogen and other molecules (Nelson et al.: J. Neurochem. 43:949-956, '84; Pentreath et al.: Neuroscience 7:759-767, '82). Iodoacetate is added to cold fixative to prevent glycogen breakdown (Cammermeyer and Fenton: Histochemistry 76:339-356, '82). This high-resolution 2DG protocol is directly compatible with many other neuroanatomical techniques. We demonstrate 2DG emulsion autoradiography combined with cytochrome oxidase (CO) histochemistry, markers for axonal pathway tracing, plastic embedding for semithin sections, and immunohistochemical staining for glutamate decarboxylase (GAD). The method should be compatible with antibodies for other antigens and with other neuroanatomical stains. To collect the data directly from microscope slides, a computer-controlled microscope was integrated with image-processing software to eliminate the need for manual counting and scoring of autoradiograms. Regions of interest are scanned automatically at high resolution to map regional labeling and/or stain density. There is excellent correspondence between computer-enhanced two-dimensional maps of the data and the original autoradiograms. Automated counts for five specimens were compared to counts of labeled cells by trained observer. The correlation between the two sets of measurements is high (r = .93). Automated data collection has been generalized to measure regional stain densities on the autoradiographed sections for direct comparison with silver grain density. The method is extremely flexible, especially since new image-processing strategies can be developed in software to extract the desired information from materials labeled by other methods (e.g., HRP).(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:New high-resolution 2-deoxyglucose method featuring double labeling and automated data collection. 306 65