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)

We report a quantitative cytochemical study on cytochrome oxidase and lactate dehydrogenase activities on rabbit epididymal spermatozoa during spontaneous lipid peroxidation. Our data show that during aerobic incubation both in NTP and KTP media the sperm cytochrome oxidase activity undergoes a significant decrease. The lactate dehydrogenase activity shows different cytochemical patterns in comparison between the two media considered. Such activity significantly increases in rabbit spermatozoa suspended in NTP medium from the first until the sixteenth hour of incubation time. At the following times the lactate dehydrogenase activity significantly declines showing yet until the later times of incubation integrated optical density values fairly high. During the whole period of the aerobic incubation, the spermatozoa suspended in medium KTP show lactate dehydrogenase integrated optical density values which not significantly differ from those of the control in spite of an initial enhancement from the first until the thirteenth hour of the experimental treatment.
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PMID:Cytochrome oxidase and lactate dehydrogenase activities in peroxidized rabbit epididymal spermatozoa. 254 15

Near-infrared spectroscopy is a noninvasive monitoring technique that allows quantitative measurement of changes in cerebral oxygenated Hb (HbO2), deoxygenated Hb (Hb), total Hb, and oxidized cytochrome aa3 (CytO2). Changes in cerebral Hb oxygenation and CytO2 have been measured in human neonates and infants under a variety of conditions. However, the association of these measurements with cerebral high-energy phosphate loss is not known. We studied simultaneous changes in cerebral HbO2, Hb, total Hb, and CytO2 by near-infrared spectroscopy and changes in nucleoside triphosphate (NTP, mostly ATP) and phosphocreatine (PC) concentrations and intracellular pH by in vivo 31P-labeled magnetic resonance spectroscopy. Four-wk-old piglets (n = 8) underwent sequential hypoxic episodes of increasing severity (inspired O2 concentration, 12, 8, 6, 4, and 0%). Animals were anesthetized and mechanically ventilated. At all levels of hypoxia, cerebral HbO2 decreased, and Hb increased. Loss of PC or NTP was not observed until inspired O2 concentration was decreased to less than 12%. With such severe hypoxia, hypotension, intracellular acidosis, and increasingly severe PC and NTP depletions occurred. Decreases in PC and NTP correlated closely with decreased CytO2 and arterial blood pressure (p < 0.0001) but not with changes in HbO2 and Hb. In conclusion, cerebral hypoxemia is readily detected by near-infrared spectroscopy as a decrease in HbO2 and an increase in Hb. However, relative changes in cerebral HbO2 and Hb have low predictive value for cerebral energy failure. Reduction of CytO2 is highly correlated with decreased brain energy state and may indicate impending cellular injury.
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PMID:Reduction of cytochrome aa3 measured by near-infrared spectroscopy predicts cerebral energy loss in hypoxic piglets. 778 31

Alteration in hepatic cellular adenosine triphosphate (ATP) levels has been shown to be a sensitive index for hypoxic damage. Hepatic ATP metabolism can be monitored by 31P nuclear magnetic resonance (NMR). Near-infrared spectroscopy (NIRS) can measure tissue oxyhemoglobin (HbO2), deoxyhemoglobin (Hb), and cytochrome oxidase (Cyt Ox), which reflect ATP production. In this study, hepatic oxygenation parameters have been correlated with ATP metabolism under graded hypoxia. Sprague-Dawley rats underwent laparotomy for liver exposure. NIRS probes and an NMR coil were placed on the liver and the animal was positioned in the NMR magnet. Graded hypoxia was achieved by a stepwise reduction of the fraction of inspired oxygen (FiO2) from 15 to 4%. Recovery between the hypoxic periods was achieved using 30% oxygen. Hepatic tissue oxygenation parameters were measured continuously by NIRS; 31P-NMR spectra obtained at 1 min intervals from energy metabolites and intracellular pH were calculated. All the hypoxic grades produced an immediate reduction in HbO2 with a simultaneous increase in Hb. Cyt Ox was reduced significantly only with FiO2 of </= 10%. 31P-NMR spectra showed a significant decrease in cellular beta nucleoside triphosphate (beta-NTP) only with FiO2 of </= 10%. Significant correlation was seen between beta-NTP and HbO2 (r=0.85), Hb (r=-0.74), and Cyt Ox (r=0.81). Cyt Ox was reduced with intracellular hypoxia and correlated temporally with the reduction of cellular beta-NTP, and therefore could be used as an index for the changes in beta-NTP with hypoxia.
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PMID:Effect of graded hypoxia on the rat hepatic tissue oxygenation and energy metabolism monitored by near-infrared and 31P nuclear magnetic resonance spectroscopy. 1172 40