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)

The histochemical localization of some oxidoreductases was investigated in the epididymides of adult tomcats. Succinate dehydrogenase, lactate dehydrogenase, beta-hydroxybutyrate-dehydrogenase revealed their highest activity in corpus and cauda epididymidis whereas glucose-6-phosphate-dehydrogenase was strongest in the caput. The activity of the diaphorases and of cytochrome oxidase in the epididymal epithelium increased from caput towards the cauda epididymidis. The reaction for isocitrate dehydrogenase was distinct throughout the whole length of the ductus epididymidis. Our findings were compared with the biochemical results of other authors and the functions of the oxidoreductases in the epididymal epithelium were briefly discussed.
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PMID:[Enzyme histochemical studies on the epithelium of the epididymis of the tomcat (author's transl)]. 43 79

In Eutherian (mammalian) spermatozoa, maturation and capacitation are associated to modifications of the metabolic activities. In order to demonstrate such variations, a quantitative cytochemical study was carried out on cytochrome oxidase and L-lactate dehydrogenase activities in mouse spermatozoa collected from the male and female genital tracts and at different times of the in vitro capacitation. Microdensitometric measurements were made on a Vickers M85 integrator microdensitometer at lambda = 480 +/- 5 nm and lambda = 585 +/- 5 nm wavelengths for the cytochrome oxidase and LDH activities, respectively. The cytochrome oxidase activity first decreases and then increases significantly both during maturation and during capacitation in vivo and in vitro. The LDH activity decreases significantly and gradually in the male and female genital tracts as well as in the course of in vitro capacitation where, however, an enhancement in the anaerobic glycolysis occurs.
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PMID:Microphotometric study on cytochrome oxidase and lactate dehydrogenase activities in mouse spermatozoa during maturation and in vivo and in vitro capacitation. 254 Jun 4

Concentrations of high-energy phosphates and activities of key enzymes of energy metabolism were assessed in hearts from species with differing levels of cardiac power output. Positive correlations were found between resting power output and the total adenylate pool and between citrate synthase activity and the total adenylate pool. Maximum in vitro activity levels of enzymes from energy metabolism were compared with calculated resting cardiac power output and maximal cardiac power output (as reflected by total oligomycin-insensitive adenosine-triphosphatase activity). Three indexes of carbohydrate metabolism (hexokinase, pyruvate kinase, and L-lactate dehydrogenase) all plateau at relatively low levels of energy demand. In contrast, enzymes required for aerobic fatty acid metabolism, (carnitine palmitoyltransferase and 3-hydroxyacyl-CoA dehydrogenase) and for tricarboxylic acid and electron transport (citrate synthase and cytochrome-c oxidase) show consistent increases as ATP demand is elevated. It appears that as capacity for power development by vertebrate hearts, increases across taxa, the elevated demand for ATP is met by expansion of fatty acid based aerobic metabolism and not carbohydrate metabolism.
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PMID:Matching of vertebrate cardiac energy demand to energy metabolism. 295 61

The neurotoxin, 6-hydroxydopamine (6-OHDA) has been implicated in the neurodegenerative process of Parkinson's disease. The current study was designed to elucidate the toxicological effects of 6-OHDA on energy metabolism in neuroblastoma (N-2A) cells. The toxicity of 6-OHDA corresponds to the total collapse of anaerobic/aerobic cell function, unlike other mitochondrial toxins such as MPP+ that target specific loss of aerobic metabolism. The toxicity of 6-OHDA paralleled the loss of mitochondrial oxygen (O2) consumption (MOC), glycolytic activity, ATP, H+ ion gradients, membrane potential and accumulation of the autoxidative product, hydrogen peroxide (H2O2). Removing H2O2 with nonenzymatic stoichiometric scavengers, such as carboxylic acids, glutathione and catalase yielded partial protection. The rapid removal of H2O2 with pyruvate or catalase restored only anaerobic glycolysis, but did not reverse the loss of MOC, indicating mitochondrial impairment is independent of H2O2. The H2O2 generated by 6-OHDA contributed toward the loss of anaerobic glycolysis through lipid peroxidation and lactic acid dehydrogenase inhibition. The ability of 6-OHDA to maintain oxidized cytochrome c (CYT-C-OX) in its reduced form (CYT-C-RED), appears to play a role in mitohondrial impairment. The reduction of CYT-C by 6-OHDA, was extensive, occurred within minutes, preceded formation of H2O2 and was unaffected by catalase or superoxide dismutase. At similar concentrations, 6-OHDA readily altered the valence state of iron [Fe(III)] to Fe(II), which would also theoretically sustain CYT-C in its reduced form. In isolated mitochondria, 6-OHDA had negligible effects on complex I, inhibited complex II and interfered with complex III by maintaining the substrate, CYT-C in a reduced state. 6-OHDA caused a transient and potent surge in isolated cytochrome oxidase (complex IV) activity, with rapid recovery as a result of 6-OHDA recycling CYT-C-OX to CYT-C-RED. Typical mitochondrial toxins such as MPP+, azide and antimycin appeared to inhibit the catalytic activity of ETC enzymes. In contrast, 6-OHDA alters the redox of the cytochromes, resulting in loss of substrate availability and obstruction of oxidation-reduction events. Complete cytoprotection against 6-OHDA toxicity and restored MOC was achieved by combining catalase with CYT-C (horse heart). In summary, CYT-C reducing properties are unique to catecholamine neurotransmitters, and may play a significant role in selective vulnerability of dopaminergic neurons to mitochondrial insults.
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PMID:The role of oxidative stress, impaired glycolysis and mitochondrial respiratory redox failure in the cytotoxic effects of 6-hydroxydopamine in vitro. 1503 17

The activity of the enzymes of the energy and carbohydrate metabolisms (cytochrome-c oxidase, L-lactate dehydrogenase, aldolase, and glycerol-1-phosphate dehydrogenase) have been studied in White Sea herring (the 1+, 2+, and 3+ age groups) sampled in Onega Bay, Dvina Bay, and Kandalaksha Bay of the White Sea. The bays differ in the hydrological regime, ecological and feeding conditions. The individual variability of the enzyme activity was the largest in the herring of the age 1+. The flexibility of the intensity and vector of the basic metabolic reactions probably supports the energy homeostasis, preconditions the switching to the most effective way of using the resources, and regulates the synthesis of the structural and storage molecules, as well as vectors the adaptation strategy of herring specimens of each age group to the hydrological regime, environment, and feeding conditions of the particular bay, corresponding to their age-related characteristics.
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PMID:Characteristics of the energy metabolism of the White Sea herring Clupea pallasii marisalbi Berg (Clupeiformes, Clupeidae) of Onega Bay, Dvina Bay, and Kandalaksha Bay of the White Sea. 2759 25