Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:1.6.99.3 (diaphorase)
 5,903 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Mitoplasts were prepared from 3-h ischemic livers in an attempt to define the structural alterations in the inner membrane that may account for the functional deficiencies of ischemic mitochondria. Mitoplasts from both control and ischemic livers had similar specific activities of cytochrome oxidase and succinate-cytochrome c reductase. With both preparations, the specific activity of rotenone-insensitive NADH-cytochrome c reductase was 10-fold lower than in the mitochondria from which they were prepared. Ischemic mitoplasts had no respiratory control with ADP, and had a slightly reduced phospholipid to protein ratio and an increased cholesterol to protein ratio. As a result, the cholesterol to phospholipid molar ratio was increased from the control of 0.04 to 0.08. There were also differences in the content of individual phospholipid species. Phosphatidylcholine increased by 15%, while cardiolipin decreased by 60%. There were increases in sphingomyelin and in the lysophospholipids of phosphatidylcholine, ethanolamine, and cardiolipin. Pretreatment with chlorpromazine did not prevent these changes. Linoleic acid was decreased by 35% in ischemic phospholipids, and the content of free fatty acids was increased 4-fold. Electron spin resonance spectroscopy of mitoplasts spin labeled with either 5- or 12-doxyl stearic acid revealed an increased molecular order (decreased fluidity) of ischemic inner mitochondrial membranes consistent with the increased cholesterol to phospholipid ratio. The data indicate activation of a phospholipase A in ischemic mitochondria with the resulting accumulation of products of lipid hydrolysis. This conclusion further emphasizes the close similarity between the structural and functional consequences of ischemia in the intact animal and the effect on isolated mitochondria of the activation of the endogenous phospholipase A. In both cases the major functional alterations are attributable to changes in the permeability of the inner mitochondrial membrane induced by the accumulation of lysophospholipids.
 ...
PMID:Structural alterations of the inner mitochondrial membrane in ischemic liver cell injury. 298 20

The report deals with the effect of ischemia and reperfusion on purified sarcolemma obtained from canine myocardium of perfused supported heart preparations. Perfusion was carried out with a perfluorochemical (FC-43). Ischemia was produced by intermittent total clamping of inflow and outflow followed by release until the decrease in dP/dtmax had become stabile. Purity of sarcolemmal vesicles was ascertained with marker enzymes: succinate cytochrome c reductase (for mitochondria), K+-stimulated p-nitrophenylphosphate (K+-pNPPase), (Na+/K+)ATPase and adenylate cyclase (for SL). In addition Na+/Ca2+-exchange characteristics for SL were determined. Sidedness of vesicles was ascertained by means of adenylate cyclase activity using sarcolemmal preparations treated and untreated with alamethicin. Emphasis was placed on ATP-dependent Ca2+ uptake, phosphorylation of sarcolemmal vesicles and yield of SL proteins. Ischemia and reperfusion resulted in a significant reduction in adenylate cyclase activity. This decline was significant following ischemia and reperfusion. The yield of protein recovered from SL vesicles from ischemic-reperfused heart preparations was also significantly decreased. Both initial rate of ATP-dependent Ca2+ uptake and maximal Ca2+ uptake fell significantly following ischemia and reperfusion. The initial rate of phosphorylation also dropped significantly. These disturbances in SL Ca2+ transport following ischemia and reperfusion are probably a part of the general deficit in Ca2+ translocation.
 ...
PMID:The effect of ischemia and reperfusion on sarcolemmal function in perfused canine hearts. 300 67

Complex I (NADH-ubiquinone reductase) is a complex system located in the inner mitochondrial membrane and has the ability to catalyse several different enzymatic reactions concerned in electron transport. It is known to be one of the first components of the respiratory chain to be damaged by ischemia. Our results, using autolysis in the rat heart as experimental model, indicate that the NADH dehydrogenase system was impaired relatively early during ischemia while transhydrogenation and NADPH dehydrogenation appeared to be relatively resistant.
 ...
PMID:Changes in NADH-ubiquinone reductase (complex I) with autolysis in the rat heart as experimental model. 309 11

After ischemia (3, 6, 9 and 12 h) of the hind extremities in dogs with a subsequent revascularization for 2 h, enzymatic activity of hepatocytes changes. After ischemia for 3 h the enzymatic activity increases. Restoration of the blood flow at later stages of the experiment results in a progressive decrease of dehydrogenase and diaphorase activities. To a greater extend the changes of the enzymatic activity are observed in perivenular hepatocytes (in the 3d zone of the hepatic acinus).
 ...
PMID:[Changes in hepatocyte dehydrogenase activity in different zones of liver acini during the revascularization of ischemic extremities]. 341 96

To evaluate the diagnostic role of histochemically demonstrated aerobic dehydrogenases in ischemic myocardial injury NADH-diaphorase, succinate dehydrogenase (SDH), beta-hydroxybutyrate dehydrogenase (HBDH) and malate dehydrogenase (MDH) were demonstrated histochemically and the corresponding enzyme activities were measured biochemically in isolated perfused rats hearts after global ischemia from 0 to 12 h. The present data show that the enzyme-histochemical methods when used properly are more sensitive indicators of early ischemic injury than classical histological staining procedures. From the enzymes tested here the histochemical demonstration of HBDH turned out to be best suited for use when suspecting ischemic myocardial injury at autopsy.
 ...
PMID:Oxidative enzyme activities and respective histochemical reactions in ischemic rat myocardium. 342 4

The results of quantitative histoenzymologic investigations of succinate dehydrogenase, lactate dehydrogenase and NAD-diaphorase in cardiomyocytes of dogs with acute experimental arterial occlusion in ischemic and postischemic periods are reviewed. An increased activity of dehydrogenases in the early periods (3,6 h) of ischemia and during recirculation was established, with its noticeable reduction at later terms (9,12 h). Medical correction of postischemic disorders was shown to improve cardiomyocyte metabolism.
 ...
PMID:[Changes in the dehydrogenase activity of cardiomyocytes during acute experimental arterial occlusion of extremities]. 373 May 53

Histochemical study of enzymatic activity in the myocardium was performed in sudden cardiac death. Human hearts in which there were no macroscopic and histological focal or diffuse changes served as material. The following enzymes were studied in the anterior or posterior walls of the left ventricle or in the interventricular septum: succinate dehydrogenase, lactate dehydrogenase (LDH), beta-hydroxybutyrate dehydrogenase (OHBDH), alpha-glycerophosphate- and glucose-6-phosphate dehydrogenase, NAD-diaphorase and phosphorylase. Increased activity of OHBDH and LDH was found: 36,0 and 22,6% higher than in trauma and brain hemorrhage that served as control. These alterations seem to be connected with the increase of blood content of fatty acids, and lactate as a response to the catecholamine excess. Foci of an acute ischemia were found in the interventricular septum in 80% of cases in which phosphorylase was revealed. The appearance of the ischemic foci was obviously due to the coronary arteries contraction.
 ...
PMID:[Histoenzymological characteristics of the myocardium in sudden cardiac death]. 405 12

Changes in the maximal rate of some cerebral enzymatic activities related to 400ene transduction and neurotransmission (lactate dehydrogenase; citrate synthase and malate dehydrogenase; total NADH-cytochrome c reductase and cytochrome oxidase; glutamate dehydrogenase; acetylcholine esterase) were assayed both in the crude or purified mitochondrial fraction and in the crude synaptosomal fraction from rat whole brain or cerebral cortex. The evaluations were performed in rats before and after a postdecapitative normothermic ischemia of 5, 10, 20 and 40 min duration. Modification observed in some of these activities wer discussed for comparison with other experimental results from different researchers. At present no definite conclusions can be drawn, but certainly the observed modifications in activity of enzymes are not passive but expression of deranged metabolism of ischemic neurons.
 ...
PMID:Brain enzymes and ischemia. 626 30

The effects of complete ischemia and of in vivo pharmacological treatment with trimetazidine were studied on some enzymatic activities related to energy transduction: lactate dehydrogenase for anaerobic glycolysis; citrate synthase and malate dehydrogenase for the Krebs' cycle; total NADH-cytochrome c reductase and cytochrome oxidase for the electron transport chain; glutamate dehydrogenase for amino acid metabolism and acetylcholine esterase for acetylcholine metabolism. These enzymatic activities were evaluated in brains of 10-day-old rats, at three different subcellular levels: homogenate in toto, purified mitochondrial fraction, crude, synaptosomal fraction. Complete normothermic post-decapitative ischemia of 30 min duration increased the activity of cytochrome oxidase in the homogenate in toto and increased the activities of citrate synthase and malate dehydrogenase in the purified mitochondrial fraction, the activities of the enzymes evaluated in the crude synaptosomal fraction being unaffected. The i.p. treatment with trimetazidine (at the dose level of 50 mg . kg-1) was without any significant effect on the tested enzymatic activities.
 ...
PMID:Effects of ischemia and pharmacological treatment on subcellular fractions from neonatal rat brain. 628 22

The maximal rate of some cerebral enzymatic activities related to energy transduction (hexokinase; phosphofructokinase; lactate dehydrogenase; citrate synthase; malate dehydrogenase; total NADH-cytochrome c reductase; cytochrome oxidase), amino acid metabolism (glutamate decarboxylase; glutamate dehydrogenase) and cholinergic metabolism (acetylcholine esterase) were tested in the cerebral cortex and in sub-cortical area of rats. The evaluations were performed both in the homogenate in toto and in the crude mitochondrial fraction, before and after a postdecapitative normothermic ischemia of 5, 10, 20, and 40 min duration. The results are discussed also with respect to the pharmacological pretreatment with two biological substances which may modulate amino acid (L-alanine) and phospholipid metabolism (CDP-choline). The analysis of the present data suggests the occurrence in brain tissue of a variety of interrelated factors implicated in the ischemia-induced changes of the maximal rate of the enzymatic activities related to the energy transduction. These include: (a) rearrangement of the enzymatic activities because of the changed metabolic and chemico-physical condition; (b) decrease in the activity of enzymes related to the electron transfer chain and glycolysis; (c) changes in enzymes related to mitochondrial membranes. The effects of in vivo administration of alanine or CDP-choline, even if significant, are not consistent throughout the time period studied.
 ...
PMID:Changes induced by ischemia on some cerebral enzymatic activities related to energy transduction and amino acid metabolism. 685 30


<< Previous 1 2 3 4 5 6 7 8 Next >>