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)

Peroxisome proliferation has been induced with 2-methyl-2-(p-[1,2,3,4-tetrahydro-1-naphthyl]-phenoxy)-propionic acid (Su-13437). DNA, protein, cytochrome oxidase, glucose-6-phosphatase, and acid phosphatase concentrations remain almost constant. Peroxisomal enzyme activities change to approximately 165%, 50%, 30%, and 0% of the controls for catalase, urate oxidase, L-alpha-hydroxy acid oxidase, and D-amino acid oxidase, respectively. For catalase the change results from a decrease in particle-bound activity and a fivefold increase in soluble activity. The average diameter of peroxisome sections is 0.58 +/- 0.15 mum in controls and 0.73 +/- 0.25 mum after treatment. Therefore, the measured peroxisomal enzymes are highly diluted in proliferated particles. After tissue fractionation, approximately one-half of the normal peroxisomes and all proliferated peroxisomes show matric extraction with ghost formation, but no change in size. In homogenates submitted to mechanical stress, proliferated peroxisomes do not reveal increased fragility; unexpectedly, Su-13437 stabilizes lysosomes. Our results suggest that matrix extraction and increased soluble enzyme activities result from transmembrane passage of peroxisomal proteins. The changes in concentration of peroxisomal oxidases and soluble catalase after Su-13437 allow the calculation of their half-lives. These are the same as those found for total catalase, in normal and treated rats, after allyl isopropyl acetamide: about 1.3 days, a result compatible with peroxisome degradation by autophagy. A sequential increase in liver RNA concentration, [14C]leucine incorporation into DOC-soluble proteins and into immunoprecipitable catalase, and an increase in liver size and peroxisomal volume per gram liver, characterize the trophic effect of the drug used. In males, Su-13437 is more active than CPIB, another peroxisome proliferation-inducing drug; in females, only Su-13437 is active.
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PMID:Structure, composition, physical properties, and turnover of proliferated peroxisomes. A study of the trophic effects of Su-13437 on rat liver. 0 Apr 6

The post-nuclear fraction of rat heart tissue was fractionated by isopycnic zonal centrifugation in sucrose gradients, followed by differential centrifugation of the zonal fractions (rho-S fractionation). The distribution of 5 lysosomal acid hydrolases, a protease with neutral and alkaline activity and several marker enzymes for cell organelles (catalase, Ca2+-ATPase, cytochrome oxidase, glucose-6-phosphatase and muramidase) were studied. Three major lysosomal populations were described with equilibrium densities of 1.09, 1.17, and 1.23 gms cc-1 (omega2t = 1.54 X 10(11) rad2 sec-1), and a continuum in the size of these particles at the three different densities.
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PMID:Distribution of lysosome populations in rat cardiac tissue. 0 60

The effect of complete subphrenic vagotomy and simultaneous pyloromyotomy on the morphological state and the activities of some intracellular enzymes of the albino rat was studied histochemically. Within the first weeks after vagotomy, the pancreatic acini were found to diminish in size, and the beta-cells in the islets of Langerhans became oedematous. In the acini, the activities of succinate dehydrogenase, cytochrome oxidase, AS naphthol acetate esterase, and glucose-6-phosphatase were observed to decline, but the reactions for beta-glucuronidase and aryl sulphatase showed intensifications and polymorphic behaviour both in acinar and in islet cells. The latter also and particularly the beta-cells simultaneously revealed enhanced activities of succinate dehydrogenase, cytochrome oxidase, beta-glucuronidase, and aryl sulphatase, and an entire disappearance of the reaction for glucose-6-phosphatase. The alpha-cells increased their AS naphthol acetate esterase activity. After 5 weeks following vagotomy, morphological and enzymatic changes in the acini and islets were negligible, and after 5 and 9 months no differences were noted between the vagotomized rats and the control animals.
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PMID:Histochemical studies on the albino rat pancreas in different periods following vagotomy and simultaneous pyloromyotomy. 17 15

The PolytronR and Dounce homogenizers have been evaluated for preparation of homogenates of rat liver prior to isolation of subcellular fractions by differential centrifugation. Marker enzymes used to evaluate the subcellular fractions included cytochrome oxidase, monoamine oxidase, D-amino acid oxidase, acid phosphatase, glucose-6-phosphatase, ethyl morphine demethylase, and lactate dehydrogenase. No significant difference in the distribution of enzymes (percent recovery or specific activity) was observed between the two methods of homogenization. In addition, there were no significant differences in the ultrastructural appearances and respiratory control ratios of the mitochondrial fractions prepared by the two methods of homogenization.
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PMID:Preparation of subcellular fractions from rat liver: comparison of the Polytron with the Dounce homogenizer. 18 48

Morphologic studies of the developing, gestational, and involuting corpus luteum show that rapid structural changes occur and that involution is not associated with an appropriate inflammatory response. Histochemical techniques were used to demonstrate several patterns of enzyme activity. The luteunized granulosa cells stained with increasing intensity for lactic dehydrogenase, succinic dehydrogenase, cytochrome oxidase, glucose-6-phosphatase, and 3 beta-hydroxysteroid dehydrogenase, but reactivity for these enzymes dropped markedly with early involution, and staining was never conspicuous in the organizing cavity. Reactions for acid phosphatase, glucosaminidase, galactosidase, glucuronidase, and nonspecific esterase were also present in the developing corpus luteum, but staining decreased more slowly during involution and was prominent in the occasional macrophages in the granulosa and the granulation tissue in the cavity. Staining was moderately intense for all of the enzymes in the corpus luteum of pregnancy. The decrease in activity for these metabolic enzymes confirms the histologic impression of degeneration, but the loss of staining for lysosomal enzymes was more rapid than expected. The latter finding complicates the hypothesis of involution of involution of the corpus luteum as an example of programmed cell death.
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PMID:Observations on the human corpus luteum: histochemical changes during development and involution. 18 5

The purpose of this experimental investigation was to provide a purified plasma membrane fraction containing a highly hormone-responsive adenylate cyclase system. Bovine adrenal cortex was homogenised and a washed pellet (450 000 X g - min) was fractionated by zonal centrifugation in a sucrose and dextran gradient. Adenylate cyclase activity was purified up to 60-fold to a specific activity of 55, 340 and 210 pmol of adenosine 3':5'-monophosphate (cyclic AMP) produced/minute per mg of protein at 38 degrees C for the basal, adrenocorticotrophin and fluoride-activated states, respectively. The time course of the adenylate cyclase activity is linear. The concentration necessary for half-maximal stimulation by adrenocorticotrophin-(1-24)-tetracosipeptide is 0.5 muM. The high hormone-responsiveness of the membrane preparation allows one to demonstrate activation of adenylate cyclase by very weakly agonistic adrenocorticotrophin fragments. The F- activated state can be detergent-dispersed by Lubrol and shows a Km (ATP) different from that of either the basal or adrenocorticotrophin-stimulated state. Other marked enzymes such as 5'-nucleotidase, glucose-6-phosphatase and cytochrome oxidase were followed during purification. The plasma membrane fraction shows rather homogeneous, relatively large vesicles (mean diameter 0.5 mum). It contains high-affinity binding sites for angiotensin II (about 2 pmol per mg protein) with an apparent association constant of 2 X 10(7) (1/mol) at 12 degrees C. The yield, 20 mg of membrane protein per preparation, may make it a tool in either affinity-labelling studies with the peptide hormones mentioned or the starting point for solubilisation and purification of adenylate cyclase.
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PMID:Purification of bovine adrenal-cortex plasma-membrane vesicles containing a highly corticotropin-sensitive adenylate-cyclase system and angiotensin-II-binding sites. 19 4

When chickens are infected with the coccidial parasite Eimeria necatrix, the plasma membrane of intestinal cells harbouring second-generation schizonts becomes refractory to mechanical shearing, hypotonic shock and ultrasonication. Plasma membrane from these infected cells was isolated to high purity as judged by enriched levels of ouabain-sensitive (Na+ + K+)-stimulated Mg2-dependent ATPase activity and sialic acid content, the lack of detectable cytochrome oxidase and glucose-6-phosphatase activities and electron microscopic analysis of the final preparation. Wide-angle X-ray diffraction patterns recorded from the isolated membranes revealed that during the later stages of parasite maturation the host cell plasma membrane acquires increasing proportions of gel-phase lipid. By contrast, purified membrane from isolated parasites is in a liquid-crystalline state. The transition temperature of host cell plasmalemma at 100 h postinfection is 61 degrees C, about 20 degrees C above physiological temperature. By contrast, liposomes of plasma membranes from infected cells undergo a thermal transition at about 28 degrees C. The accumulation of gel-phase lipid in the host cell plasma membrane is not attributable either to an increase in the constituent ratio of saturated to unsaturated fatty acids or to a significant change in the cholesterol to phospholipid ratio. During the late stages of infection, the cells become stainable with trypan blue which suggests that the acquisition of crystalline phase lipid disrupts the permeability of the host cell plasmalemma.
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PMID:Induction of gel-phase lipid in plasma membrane of chick intestinal cells after coccidial infection. 48 63

Homogenates of HTC cells have been fractionated by differential centrifugation (in four particulate fractions: N, M, L, P, and a supernatant S) or isopycnic banding in linear sucrose gradients. On this basis, the following subcellular organelles may be characterized: (i) Mitochondria, detected by cytochrome oxidase and succinodehydrogenase, are collected in the M and L fractions, and equilibrate, as a narrow band, at a median buoyant density of 1.18 g/cm3. (ii) Lysosomes, detected by the latent hydrolases beta-glycerophosphatase and N-acetyl-beta-glucosaminidase, are largely sedimented in the M and L fractions, and display a broad density distribution pattern with a median value of 1.17 g/cm3. This density is decreased or increased after cultivation of the cells in presence of Triton WR-1339 or Dextran 500, respectively. The behavior of cathepsin D is somewhat at variance with that of the two other hydrolases. (iii) Plasma membrane is tentatively detected by alkaline phosphodiesterase I. Largely recovered in the P fraction, this enzyme equilibrates at a median density close to that of the lysosomal hydrolases; the bulk of cholesterol and about half of the leucyl-2-naphthylamidase are closely associated with alkaline phosphodiesterase I; HTC cells do not contain typical 5'-nucleotidase. (iv) Catalase-bearing particles, of high buoyant density (1.22 g/cm3) are present, but 30-40% of the catalase is also found readily soluble. NADPH- and NADH: cytochrome c reductase, and RNA show more complex distributions. It is suggested that the former enzyme is associated with the endoplasmic reticulum; as in liver, NADH reductase activity is shared between the endoplasmic reticulum and the mitochondria; half of the RNA is associated with free ribosomes of polysomes. True glucose-6-phosphatase could not be detected.
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PMID:Analytical fractionation of cultured hepatoma cells (HTC cells). 56 43

An analysis of starvation and starvation followed by refeeding was undertaken to characterize some organismic, organ, and mitochondrial responses to these two circumstances. Body weight, organismic respiration as well as weight protein and succinic dehydrogenase activity for liver, kidney, and heart were determined over the course of 6 days of starvation and 5 days refeeding for adult male rats. Assays of marker enzyme activities for mitochondria (cytochrome oxidase), lysosomes (acid phosphatase), endoplasmic reticulum (glucose-6-phosphatase), and plasma membranes (5'-nucleotidase) were conducted for liver in addition to quantitations of mitochondrial protein. All enzyme determinations were done on whole tissue homogenates and reported as total organ activity. Liver mitochondria were harvested quantitatively directly from whole liver homogenates by zonal centrifugation for determination of mitochondrial protein. Starvation resulted in a major loss of body weight, organ weight, and organ protein; liver greater than kidney greater than heart. These changes were accompanied by a major reduction in organ succinic dehydrogenase activity; liver greater than kidney. In heart, succinic dehydrogenase was doubled in activity at day 2 of starvation and subsequently diminished to values not significantly lower than controls. In liver, mitochondrial mass (protein) was severely diminished. From analysis of marker enzyme activities, it appeared that lysosomes, endoplasmic reticulum, and plasma membrane were also decreased. Refeeding restored the greatest part of these losses within 5 days.
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PMID:Starvation and refeeding in rats: effect on organismic respiration, cytoplasmic constituents of liver, and succinic dehydrogenase activity in liver, kidney, and heart. 70 2

Pollen grains and pollen tubes of Pinus roxburghii were subjected to histochemical technique with a view to determining the distributional pattern of reserve substances (ascorbic acid, proteins starch, polysaccharides, nucleic acids) and some enzymes (acid phosphatase, glucose-6-phosphatase, peroxidase, esterase, cytochrome oxidase, succinate dehydrogenase). An attempt is made to correlate the activity of different enzymes in relation to pollen tube growth.
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PMID:Studies on the physiology of pollen and pollen tube growth. 1. pinus roxburghii. 82 83


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