Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:1.3.5.1 (succinate dehydrogenase)
 8,177 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Cytophotometric measurements of the activities of 5 oxidative enzymes (succinate, malate, lactate, NAD+-linked isocitrate and NADH dehydrogensases) have been made in anterior horn cells of the lumbar and cervical spinal cord of the rabbit. The thickness of tissue sections was measured by an interference microscope and various optical and chemical precautions were taken to diminish the possible errors that might be involved in cytophotometry. The findings of the study indicated a unimodal distribution of the activities of all of the enzymes studied in anterior horn cells, though there was a wide range of enzyme concentration among different cells. Thus the findings in the rabbit are consistent with the "constant proportion" hypothesis of the activity of certain oxidative enzymes, and are contrary to a previous finding that there may be two populations of succinate dehydrogenase-containing anterior horn cell.
 ...
PMID:Quantitative oxidative enzyme histochemistry of the spinal cord. Part 1. Distribution of enzyme activity in anterior horn cells. 117 86

The inhibitory effect of cationic proteins from rabbit polymorphonuclear leucocytes on the oxidation of NADH by staphylococcal membrane preparations is described. Both cyanide and haematin are shown to interfere with the inhibitory process, by different mechanisms. Other authors have shown that glucose repressed staphylococci are diverted to a fermentative mode of metabolism. These findings were confirmed by demonstrating that membrane preparations from staphylococci grown in the presence of glucose have diminished cytochrome and succinic dehydrogenase levels. From a comparison of the effect of the cationic proteins on NADH oxidation in membrane preparations from organisms grown normally and under conditions of glucose repression, and from knowledge of the different susceptibility to the cationic proteins of the two types of organisms, it is suggested that the cationic proteins exert their bactericidal action on staphylococci following an energy dependent binding to the membrane.
 ...
PMID:A study of the action of the cationic proteins from rabbit polymorphonuclear leucocytes on the staphylococcal cell membrane. 121 26

Triamcinoline acetonide (10 mg per kg of body weight a day) was administered to rabbit fed on a laboratory chow diet. The content of flavins in liver but not in kidney, muscle and brain started to decrease 24 h after a single dose. The activities of enzymes in the liver were determined: the activities of pyruvate dehydrogenase complex, lipoamide dehydrogenase (NADH:lipoamide oxidoreductase EC 1.6.4.3), NADH dehydrogenase (NADH : (acceptor) oxidoreductase EC 1.6.99.3) and D-amino acid oxidase (D-amino acid: oxygen oxidoreductase (deaminating) EC 1.4.3.3) were decreased but those of succinate dehydrogenase (succinate : (acceptor) oxidoreductase EC 1.3.99.1) and xanthine oxidase (xanthine : oxygen oxidoreductase EC 1.2.3.2) remained unchanged. The activities of enzymes in the kidney, however, remained unchanged except the decrease in the activity of pyruvate dehydrogenase complex.
 ...
PMID:Effect of triamcinolone administration on content of flavins in rabbit liver. 127 76

The experiments carried out for the study aimed at determining the prenatal sensitivity to cadmium in the aspect of beth morphological and functional condition of placenta. The experiments were carried out on 80 pregnant female rats divided into three experimental groups and a control one. The experimental animals were daily administered, intragastrically, aqueous solution of cadmium chloride, from the 7th to the 19th day of pregnancy, in doses differing between the experimental groups: 2, 10 and 22 mg of CdCl2 per kilogram of body weight, respectively. The animals were decapitated on the 21st day of pregnancy. Placenta sections, besides hematoxylin and eosin staining, were examined for the activity of the following enzymes: succinic dehydrogenase (SDH) E.C.1.3.99.1., lactate dehydrogenase (LDH) E.C.1.1.1.27., NADH-tetrazole reductase (NADH-t.r.), without a catalog number, and their glycogen reaction was checked. The results of the experiments proved cadmium chloride to cause considerable damage to the enzymatic apparatus of placenta, leading to energy deficit in the cells of both the fetal and the maternal part of this organ. The multienzymatic changes observed preceded the morphologic ones by far.
 ...
PMID:[Dynamics of morphological and cytochemical changes in the placenta following cadmium chloride intoxication]. 130 26

Structural mitochondrial damage accompanies the cytotoxic effects of several drugs including tumor necrosis factor (TNF). Using various inhibitors of mitochondrial electron transport we have investigated the mechanism of TNF-mediated cytotoxicity in L929 and WEHI 164 clone 13 mouse fibrosarcoma cells. Inhibitors with different sites of action modulated TNF cytotoxicity, however, with contrasting effects on final cell viability. Inhibition of mitochondrial electron transport at complex III (cytochrome c reductase) by antimycin A resulted in a marked potentiation of TNF-mediated injury. In contrast, when the electron flow to ubiquinone was blocked, either at complex I (NADH-ubiquinone oxidoreductase) with amytal or at complex II (succinate-ubiquinone reductase) with thenoyltrifluoroacetone, cells were markedly protected against TNF cytotoxicity. Neither uncouplers nor inhibitors of oxidative phosphorylation nor complex IV (cytochrome c oxidase) inhibitors significantly interfered with TNF-mediated effects, ruling out the involvement of energy-coupled phenomena. In addition, the toxic effects of TNF were counteracted by the addition of antioxidants and iron chelators. Furthermore, we analyzed the direct effect of TNF on mitochondrial morphology and functions. Treatment of L929 cells with TNF led to an early degeneration of the mitochondrial ultrastructure without any pronounced damage of other cellular organelles. Analysis of the mitochondrial electron flow revealed that TNF treatment led to a rapid inhibition of the mitochondria to oxidize succinate and NADH-linked substrates. The inhibition of electron transport was dose-dependent and became readily detectable 60 min after the start of TNF treatment, thus preceding the onset of cell death by at least 3-6 h. In contrast, only minor effects were observed on complex IV activity. The different effects observed with the mitochondrial respiratory chain inhibitors provide suggestive evidence that mitochondrial production of oxygen radicals mainly generated at the ubisemiquinone site is a causal mechanism of TNF cytotoxicity. This conclusion is further supported by the protective effect of antioxidants as well as the selective pattern of damage of mitochondrial chain components and characteristic alterations of the mitochondrial ultrastructure.
 ...
PMID:Cytotoxic activity of tumor necrosis factor is mediated by early damage of mitochondrial functions. Evidence for the involvement of mitochondrial radical generation. 131 87

The effects of L-carnitine on respiratory chain enzymes in muscle of long distance runners were studied in 14 athletes. These subjects received placebo or L-carnitine (2 g orally b.i.d.) during a 4-week period of training. Athletes receiving L-carnitine showed a significant increase (p < 0.01) in the activities of rotenone-sensitive NADH cytochrome c reductase, succinate cytochrome c reductase and cytochrome oxidase. In contrast, succinate dehydrogenase and citrate synthase were unchanged. No significant changes were observed after placebo administration. The levels of both total and free carnitine from athletes receiving placebo were significantly decreased (p < 0.01) after treatment. By contrast, total and free carnitine levels were markedly increased (p < 0.01) after supplementation with L-carnitine. Our results suggest that L-carnitine induces an increase of the respiratory chain enzyme activities in muscle, probably by mechanisms involving mitochondrial DNA.
 ...
PMID:Respiratory chain enzymes in muscle of endurance athletes: effect of L-carnitine. 132 42

Using isolated rat hepatocytes the biochemical effects of hydrazine have been investigated using both conventional assay techniques and high resolution proton NMR. High resolution proton NMR revealed that hydrazine caused a significant increase in alanine and lactate levels in the incubation buffer, whereas levels of beta-hydroxybutyrate were decreased. NMR also detected metabolites of hydrazine notably acetylhydrazine and a cyclised hydrazone formed with alpha-ketoglutarate. Changes were detected in NADH and NADPH, ATP, succinate dehydrogenase (SDH) and total non-protein sulphydryl groups (TNPSH). However, the changes in pyridine nucleotides occurred at higher concentrations than those affecting succinate dehydrogenase and ATP. Similarly, the depletion of TNPSH occurred at a higher concentration and with a different time course to that seen with ATP depletion and inhibition of succinate dehydrogenase.
 ...
PMID:A biochemical and NMR spectroscopic study of hydrazine in the isolated rat hepatocyte. 133 60

Endogenous cytochrome oxidase activity was investigated in the adult rat striatum at the light microscope level to see if it was distributed in accordance with the established striatal patch/matrix compartmentalisation. Striatal sections stained to visualise cytochrome oxidase activity were compared with serial sections stained to visualise tyrosine hydroxylase and calbindinD28k-like immunoreactivity, established markers of the matrix compartment. The distribution of endogenous cytochrome oxidase activity was found to coincide with the immunocytochemical staining pattern seen for tyrosine hydroxylase and calbindinD28k whereby areas of intense tyrosine hydroxylase and calbindinD28k-like immunoreactivity (termed the matrix) corresponded to areas of intense cytochrome oxidase activity. Conversely, areas of less intense tyrosine hydroxylase and calbindinD28k-like immunoreactivity (termed patches) corresponded to areas of low cytochrome oxidase activity. In addition, the distribution of two other oxidative enzymes involved in the regulation of mitochondrial respiration, succinic dehydrogenase and NADH-diaphorase, was examined in the striatum and substantia nigra by using histochemical techniques. Both NADH-diaphorase and succinic dehydrogenase histochemistry showed an uneven pattern of neuropil staining in the striatum. In the substantia nigra a few intensely stained cell bodies were seen in the dorsal-lateral tip of the pars reticulata with both histochemical techniques. By using an anti-cytochrome oxidase antibody an abundance of immunoreactive cell bodies and processes were seen in the substantia nigra, particularly in the dorso-medial rim and dorsal tip of the pars reticulata. The substantia nigra pars lateralis contained many intensely stained cytochrome oxidase-like immunoreactive cell bodies and processes.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Compartmental distribution of cytochrome oxidase in the striatum of the rat. 134 42

1,2,3,4-Tetrahydroisoquinoline (TIQ), which is structurally similar to MPTP, has been found in human brain and has been reported to inhibit the mitochondrial respiration as does 1-methyl-4-phenylpyridinium ion (MPP+). However, the potency of inhibition by TIQ is less than that of MPP+. In this study, we report the effects of N-methyl-1,2,3,4-tetrahydroisoquinoline (N-Me-TIQ) and N-methylisoquinolinium ion (N-Me-IQ+) on the mitochondrial electron transport system using mitochondria prepared from mouse brains. Five mM N-Me-TIQ and 500 microM N-Me-IQ+ inhibited complex I activity to 54% and 63% of the control, respectively. The IC50 of N-Me-TIQ and N-Me-IQ+ were approximately 6.5 mM and 650 microM, respectively. Neither substance inhibited complex II, III and IV activities. Kinetic analyses of N-Me-IQ+ on complex I activity revealed uncompetitive inhibition against NADH and non-competitive inhibition against ubiquinone. These inhibitory characteristics were the same to those of MPP+ and the inhibitory potency of N-Me-IQ+ on complex I activity was stronger than that of MPP+.
 ...
PMID:Selective inhibition of complex I by N-methylisoquinolinium ion and N-methyl-1,2,3,4-tetrahydroisoquinoline in isolated mitochondria prepared from mouse brain. 135 9

The effect of chronic left ventricular pressure overload on the activities of mitochondrial respiratory chain enzymes was investigated in myocardial biopsies from the left ventricular apex of 13 patients undergoing aortic valve replacement for aortic valve stenosis. Transvalvular pressure gradients measured by left-sided heart catheterization ranged from 52 to 100 mmHg. The specific activity of mitochondrial respiratory chain enzyme complexes I+III (antimycin A sensitive NADH cytochrome c oxidoreductase) and the myocardial concentrations of coenzyme Q10 (CoQ10) increased significantly (P < 0.05) with increasing aortic valve pressure gradient. In contrast, the specific activities of complex IV (cytochrome c oxidase), succinate dehydrogenase, and citrate synthase, a mitochondrial matrix enzyme, showed no significant correlation with the pressure gradient. Since CoQ10 is the rate-limiting compound of the activity of complexes I+III but not of cytochrome c oxidase, succinate dehydrogenase, or citrate synthase, these data suggest that the increase in the activity of complexes I+III is due to the increase in CoQ10 content.
 ...
PMID:Positive correlation between aortic valve pressure gradient and mitochondrial respiratory chain capacity in hypertrophied human left ventricle. 145 Jun 14


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