Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:Q0Z944 (hemoglobin)
 63,986 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Aminopeptidase activity of three fractions of human erythrocytes (membranes free of hemoglobin; hemolysate free of membranes; enzyme protein fraction made free of hemoglobin by DEAE-cellulose) was measured by a NADH dependent optical test using asparaginyl1-angiotension II-amide as substrate. 1. From the enzyme protein fraction 6 subfractions were obtained by (NH4)2SO4 precipitation. By measuring enzyme kinetics at three different pH-values (pH 5,0; 7,0; 8,0) with and without addition of the effectors Na2EDTA and Ca++ the existence of 6 different enzymes could be demonstrated. 2. The aminopeptidase activity of the hemolysate made free of membranes could be inhibited by diisopropylfluorphosphate and p-chloromercuribenzoate at three different pH-values (pH 5,0; 6,5; 7,0; 8,0 and 6,5; 7,0; 8,0 respectively). 3. A reduction of enzymatic activity of 20% was found after incubation at 37degreesC for two hours.
 ...
PMID:[Studies on the pH-dependence, inhibition and reactivation of angiotension II-amide splitting enzymes in human erythrocytes (author's transl)]. 1 Jun 11

Reduce nicotinamide adenine dinucleotide (NADH) fluorescence was recorded from an avascular area on the squirrel monkey cortex prior to, during, and after focal incomplete ischemia. By using the instrumentation described, stable recordings were obtained free from hemoglobin artifact and with only minimal photodecomposition. Pentobarital was compared to urethane and halothane as the anesthetic agent and was found acceptable for these types of studies in the dosages used. NADH levels were constant prior to ischemia, increased during ischemia, returned to pre-ischemic levels after restoration of blood flow, and then increased greatly at death produced by anoxia. The use of the infrared microscope for semiquantitative measurements of cortical blood flow throughout the duration of these acute studies was investigated and found to the reliable.
 ...
PMID:Reduced nicotinamide adenine dinucleotide fluorescence and cortical blood flow in ischemic and nonischemic squirrel monkey cortex. 1. animal preparation, instrumentation, and validity of model. 16 72

Normal human erythrocytes were exposed for two hours at 38 C to an atmosphere of air containing variable concentrations of nitrogen dioxide, in order to detect any primary cytoplasmic effect of NO2 on the calculated oxidation-reduction (redox) ratio ([NAD+]/[NADH]) of a mitochondria-free cell. Substantial increases in the redox ratio were noted only when NO2 concentrations exceeded 15 ppm. In the range of 15 to 500 ppm NO2, the increase in the redox ratio significantly correlated with the NO2 concentration (r=.71; p less than .01). Intracellular to extracellular anion distribution ratios for chloride, lactate, and pyruvate were similar in NO2 and non-NO2 exposed cells, suggesting absence of a substantial hemolytic effect. These data identify a direct cytoplasmic NO2-induced biochemical change that may be mediated by a mechanism other than lipid peroxidation. Alteration of hemoglobin or NAD-NADH-dependent enzyme activity is suggested.
 ...
PMID:Nitrogen dioxide and the erythrocyte redox state. 17 Aug 72

Acute changes in the redox state of NADH in the cerebral cortex of cats were investigated following occlusion of the middle cerebral cortex (MCA) and were correlated with alterations of regional cerebral blood flow in the ischemic cortex determined autoradiographically. Arterial occlusion was accomplished via the transorbital approach. Cortical fluorescence and reflected light signals were recorded from the central MCA territory by means of a beam-splitting fluorometer, and a fluorescence signal corrected for alterations in intravascular hemoglobin was derived. Following arterial occlusion, there was a rapid increase in cortical NADH fluorescence, peaking within 30 to 70 seconds at 20% to 40% of full scale. This was followed by a slow linear decline in fluorescence over the next several minutes. The behavior of cortical NADH fluorescence was unaffected by replacement of the ambient air over the cortical surface with nitrogen. Mean regional blood flow values in the most ischemic gyri two to 15 minutes following arterial occlusion were 21% to 23% of the corresponding values in the opposite, nonischemic hemisphere. In individual animals, peak NADH fluorescence values following arterial occlusion correlated with the extent of blood flow reduction in the affected ischemic gyri (P less than 0.05).
 ...
PMID:Pyridine nucleotide redox state and blood flow of the cerebral cortex following middle cerebral artery occlusion in the cat. 17 77

NADH fluorescence, sagittal sinus blood flow and sinus hemoglobin saturation were monitored simultaneously during direct cortical stimulation of a wide area of the anterior and mid suprasylvian and marginal gyri. The area monitored flurorometrically was located within the area apparently drained by the sinus, so that the flurometric changes could be correlated with oxygen consumption changes calculated from the sinus flow and saturation values. The onset and peak values of calculated oxygen consumption and NADH fluorescence changes usually occurred within several seconds of one another and high, significant (r greater than 0.9 and P less than 0.01) correlations were found between the maximum changes in both parameters following stimulation. The relation of cortical [K+]0 changes to oxygen consumption changes was also explored; again the magnitude of [K+]0 changes and calculated oxygen consumption changes correlated well. The demonstrated agreement between fluorometric and direct (sinus cannulation) measurements of oxidative metabolism reinforces the interpretation of in situ cortical fluorescence changes as indicative of changes in oxygen consumption rate
 ...
PMID:NADH fluorescence, [K+]0 and oxygen consumption in cat cerebral cortex during direct cortical stimulation. 18 Nov 14

A photographic method for measuring two-dimensional changes in NADH fluorescence and hemoglobin distributions in the rat cerebral cortex in vivo has been developed. Intracellular NADH was excited by UV light peaking at 360 nm and the emission was observed through a window with the maximum transmission at 450 nm. The fluorescence photographs (360 leads to 450 nm) required 20-25 sec exposures at the aperture opening of f/5.6 and the reflectance photographs (360 leads to 360 nm) 10 sec exposures at f/32. The digitization of photographic images was achieved either by a PDP-8-controlled microdensitometer coupled to an A/D converter or by a combination of a manually operated microdensitometer and a computer-controlled digitizer. In the latter case, a photographic negative was scanned with a Joyce-Loebl microdensitometer in parallel lines 170 mum apart, and the densitometric tracings were digitized with a PDP-8-controlled TV digitizer. The digital data were processed by DEC PDP-10 computer and the results were displayed in 3-dimensional surfaces. Nitrogen anoxia caused increases in fluorescence at 450 nm ranging from 10 to 75% fo the normoxic fluorescence intensities (after correcting for the logarithmic characteristics of the photographic films) and decreases in reflectance intensities in the range of 10-30%. The spatial resolution of the present technique is limited to approximately 30 mum X 30 mum on the cortical surface and the time resolution to 10-25 sec. The optical properties of the cerebral cortex in vivo appear to be controlled primarily by blood vessel patterns and hemodynamic factors and secondarily by the redox state of the tissue. Evidence for a heterogeneous redox response of the cerebral cortex toward N2 anoxia was obtained.
 ...
PMID:Two-dimensional analysis of the redox state of the rat cerebral cortex in vivo by NADH fluorescence photography. 18 81

Non-invasive optical techniques were used to monitor the effects of increasing cerebral energy demand on metabolic capabilities and vascular reactivity in young and aged brain. Low level of electrical stimulation of the cortex, in both young (4--7 months) and aged (24--28 months) rat brain, were accompanied by transient oxidations of NADH and cytochrome oxidase (a,a3) as measured by microfluorometry and reflection spectrophotometry respectively. Stimulation sufficient to produce spreading cortical depression was accompanied by an oxidation of both NADH and cytochrome a,a3 in young brain together with an increase in local blood volume. There was either no change or a slight disoxygenation of hemoglobin. In aged brain, however, spreading depression was associated with an oxidation of NADH and a reduction of cytochrome a,a3 together with an increase in local blood volume and an oxygenation of hemoglobin. The present results indicate that the relationship between microcirculation and the terminal oxidase step of the respiratory chain is altered in aged brain when energy demand is high.
 ...
PMID:Effects of age on brain oxidative metabolism in vivo. 21 92

The ability of the erythrocyte membrane to transfer the reducing equivalent from the outer solution into the cells was studied. Erythrocyte hemoglobin transformed into the metstate serves as the electron acceptor. The donors develop during illuminating with visible light the outer solution, containing NADH and eosin. Some precautions were made to inhibit the migration of the donor molecules through the membrane. The photoreduction of hemoglobin in erythrocytes in such conditions can be attributed to the diffusion of some lipophilic electron carriers if they exist in the membrane, or to the ability of the transmembrane proteins to mediate the electron transfer from definite donors to the acceptors.
 ...
PMID:[Photoreduction of hemoglobin in erythrocytes]. 22 35

The distance between perfusion and anoxia was measured on the border of an experimental ischemic area in the rabbit heart. Reduced nicotinamide adenine dinucleotide (NADH) fluorescence photography was used to detect myocardial anoxia. Fluorescein angiography marked areas of myocardial perfusion. The hearts were isolated, perfused with a hemoglobin-free solution and performed no external work. In all hearts there was a narrow band between areas of perfusion and anoxia that measured 329 +/- 42 mu (mean +/- SD). The transition from minimal to full NADH fluorescence was abrupt, less than 80 mu. We conclude that the normoxic/anoxic transition is sharp, and the gap between perfusion and anoxia is narrow along an ischemic border in the isolated heart performing no external work. These data suggest that in the vivo working heart the gap between perfusion and anoxia would be even narrower.
 ...
PMID:Visualization of the distance between perfusion and anoxia along an ischemic border. 22 84

Activities of delta amino levulinic synthetase (DALS), cytochrome oxidase (E. C. 1.9.3.1.), NADH cytochrome b5 reductase (NADH red.), NADPH cytochrome P450 reductase (NADPH red.), contents of cytochrome P450 (cyt. P450) and cytochrome b5 (cyt. b5), and levels of hemoglobin and hematocrit were studied in three groups of rats: a) malnourished, b) during recovery from malnutrition, and c) controls. During severe protein malnutrition blood levels of hemoglobin and hematocrit were found to be decreased as well as DALS's activity in homogenized bone marrow and liver. The activity of NADH red, and contents of cyt. P.450 and cyt. b5 in hepatic microsomes were also found significantly depressed. The microsomal activity of NADPH red. as well as mitochondrial cytochrome oxidase did not present significant changes, since values obtained in malnourished rats were similar to those found for the control group. While recovering from malnutrition, when rats were fed a casein based diet (10 NDpCalo/o) supplemented with Fe and Cu, the hepatic enzymatic activities, the cytochrome contents of P450 and b5, and hematocrit experienced a spectacular increase, reaching towards the end of the refeeding period values which could be compared to those found in the control group. Nevertheless, DALS' activity in homogenized bone marrow and hemoglobin levels remained low. Results are discussed in relation to depressed activities and contents of enzymes, coenzymes, metabolites and subtrates involved in the hemoglobin synthesis in the rat bone marrow, during recovery from malnutrition.
 ...
PMID:[Activity of delta-aminolevulinic synthetase, cytochrome oxidase and levels of the mixed function oxidase system during experimental protein malnutrition. Response to re-alimentation]. 22 23


1 2 3 4 5 6 7 8 9 10 Next >>