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PubMed1976

Preparation of anti-etiocholenic acid antiserum and anti-cholesterol succinate antiserum and their cross reactivities.

Anti-3-hydroxy 5-androstene carbonic acid (etiocholenic acid) antiserum was obtained by immunizing rabbits with anetiocholenic acid-polylysine complex. Anticholesterol succinate antiserum was also prepared by immunizing rabbits with a cholesterol succinate-polylysine complex. The cross reactivities of these antisera were examined by means of radioimmunoassay system, immunolysis of liposome and passive hemagglutination reaction. Anti-etiocholenic acid antiserum was specific against the structure of ring A of cholesterol and the nature of OH group at C3 position and anti-cholesterol succinate antiserum was specific against the side chain similar to that of cholesterol.

Androstenols↗
PubMed1982

Labeling of succinate-cytochrome c reductase with 125I. Accessibility of the peptides to the aqueous phases on the cytosolic and matrix sides of the mitochondrial membrane.

Lactoperoxidase-catalyzed radioiodination was used to study the arrangement of the component peptides of succinate-cytochrome c reductase with respect to the aqueous phases on each side of the mitochondrial inner membrane. Mitochondria depleted of their outer membrane and inside-out vesicles purified from submitochondrial particles by the lectin-affinity procedure (D'Souza, M. P., and Lindsay, J. G. (1981) Biochim. Biophys. Acta 640, 463-472) were iodinated using immobilized preparations of lactoperoxidase. The labeled membranes were solubilized in detergent and the succinate-cytochrome c reductase was purified by immunoprecipitation with specific IgG. Analysis of the radioiodine distribution after sodium dodecyl sulfate-polyacrylamide gel electrophoresis and comparison with peptide stain patterns show that bands 2 (64 kilodaltons), 6 (30 kilodaltons), 9 (15 kilodaltons), and 11 (less than 10 kilodaltons) are labeled from the cytoplasmic surface of the membrane. Bands 1 (72 kilodaltons), 4 (48 kilodaltons), and 8 (20 kilodaltons) appear to be labeled on the matrix side of the membrane, while bands 3 (52 kilodaltons), 5 (35 kilodaltons), 7 (25 kilodaltons), and 10 (11 kilodaltons) are labeled from both sides of the membrane. Tentative identification of the labeled bands suggests that band 1 is the large subunit of succinate dehydrogenase. Bands 3 and 4 represent proteins which have been referred to as core proteins I and II. Bands 5 and 6 are the proteins associated with cytochromes b and c1, respectively; band 7 is the Rieske iron-sulfur protein.

Animals↗
PubMed1982

[Role of the adenylate cyclase system in utilization of succinate by the frog gastric mucosa].

Interrelationship between the adenylate cyclase system state and utilization of succinate as a substrate of oxidation in mechanisms of HCl secretion by isolated gastric mucosa of frog Rana esculenta was studied. The inhibition of the protein synthesis by cycloheximide rendered gastric mucosa insensitive to the activation of HCl secretion by histamine and succinate. A similar effect was exerted by cimetidine, a blocking agent for H2-receptors. The blockade could be prevented with dibutyryl-cAMP. The seasonal dependence of activation of HCl secretion by specific and unspecific modifiers was discovered. The data obtained show the necessity of preliminary activation of adenylate cyclase and accumulation of limiting content of cAMP for the utilization of succinate in reactions of generation and transport of H+ by acid-producing cells of isolated gastric mucosa in frog.

Adenylyl Cyclases↗
PubMed1984

Effect of iron deficiency on succinate- and NADH-ubiquinone oxidoreductases in skeletal muscle mitochondria.

The effects of iron deficiency on the NADH- and succinate-oxidizing complexes of rat skeletal muscle mitochondria have been investigated. Both systems were similarly affected: activities were about 30% of normal in dehydrogenase, ubiquinone reductase, and oxidase assays, and similar reductions in the concentration of their respective flavin prosthetic groups were also evident in the iron-deficient membranes. Thus, the turnover numbers of the two enzymes were unchanged in iron deficiency. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed similarly reduced levels of those peptide components of Complexes I and II that could be unequivocally distinguished. Soluble beef heart succinate dehydrogenase added to alkaline-treated rat skeletal muscle mitochondrial membranes attached to binding sites exposed by the treatment, forming a hybrid complex indistinguishable from the original skeletal muscle complex, with restoration of succinoxidase and succinate-ubiquinone reductase activities to the levels observed in the original rat membranes. Iron-deficient particles behaved like the normal in these tests. No unfilled binding sites for the enzyme could be detected prior to alkaline treatment. The data are interpreted as indicating that the lower activities of these two respiratory complexes in iron deficiency are due to lower content of the enzymes rather than to the presence of impaired enzymes in the membrane, that only fully competent complexes are present in these membranes, and that iron-deficient complexes are either not assembled or are lost after assembly.

Animals↗
PubMed1984

Quantitative microphotometric succinate dehydrogenase histochemistry in human nephron.

A simple method for microphotometric evaluation of cryostat sections from human renal tissue routinely stained for succinate dehydrogenase activity by means of tetranitro-blue tetrazolium chloride is described and tested for validity. Manual absorbance measurement within single nephron segments from the same section allows to directly visualize the distribution pattern of this enzyme along the nephron. Photometric data can be expressed in relative enzyme activities by using the cortical collecting ducts within the same section as reference. This allows to compare measurements of different kidney sections stained by various incubation procedures. The agreement found between relative succinate dehydrogenase activities and recently published morphometric data on mitochondrial inner membranes along the rat nephron suggests that quantitative succinate dehydrogenase microphotometry is a useful histochemical tool for the assessment of renal mitochondrial cristae membranes.

Histocytochemistry↗
PubMed1984

[Interaction of the sulfate ion with the active site of succinate dehydrogenase].

A new type of slow changes of the succinate dehydrogenase (EC 1.3.99.1) activity induced by the sulphate ion is described. After preincubation of submitochondrial particles or soluble succinate dehydrogenase with sulphate both preparations catalyze the phenazine methosulphate reductase reaction with a significant lag. When added to the assay medium, the sulphate ion induces biphasic time-dependent competitive inhibition of the enzyme. The sulphate-induced inhibition is due to a rapid interaction of the anion with the active site of the enzyme followed by a slow pH-dependent (pKa=7.2) transformation of the enzyme-inhibitor complex. The pH-profiles of the overall succinate dehydrogenase reaction and of equilibrium between the fast and slow enzyme-sulphate complexes suggest that the same protolytic step is involved in the formation of an active intermediate and inactive enzyme-sulphate complex.

Animals↗
PubMedDate not supplied

[Effect of exogenous succinate on the contents of tricarboxylic acid cycle metabolites of the liver].

The paper deals with dynamics of tricarboxylic cycle metabolites in the liver after subcutaneous injection of succinate in a dose of 100 mg/kg to guinea pigs. Before the preparation administration the highest level was marked for succinate, malate and citrate. 3 h after the administration the succinate content increased by 57% and 6 h later it returns to the initial level. No essential changes were observed in the content of other tricarboxylic acid cycle metabolites.

Animals↗
PubMedDate not supplied

Effects of extraction of ubiquinone on succinate-ferricyanide reductase activity.

The effects of extraction and reincorporation of ubiquinone on succinate dehydrogenase of mitochondrial membranes have been studied. The succinate dehydrogenase activity, measured with ferricyanide as electron acceptor, was diminished by approximatively 75% upon the extraction of ubiquinone and was restored when ubiquinone was reincorporated into the membranes. A study in a model system represented by ubiquinols incorporated in liposomes shows that the initial rates of ubiquinol oxidation by external ferricyanide are almost two order of magnitude lower than the rates of succinate-ferricyanide reductase in mitochondria. It is therefore concluded that the compound feeding electrons to ferricyanide in damaged mitochondria is either ubiquinone in a bound form or a compound between UQ and the antimycin block.

Animals↗
PubMed1994

Insulinotropic action of the D-glucosyl and 3-O-methyl-D-glucosyl monomethyl esters of succinic acid.

Succinic acid methyl esters are currently under investigation as potential insulinotropic tools in animal models of non-insulin-dependent diabetes mellitus. The in vivo administration of these esters may result in the undesirable generation of methanol through their intracellular hydrolysis. As a first attempt to circumvert this drawback, we have now investigated whether the esterification of the carboxylic group of succinic acid monomethyl ester by D-glucose or 3-O-methyl-D-glucose affects its insulin-otropic action. Both the 6-O-D-glucosyl and 6-O-(3-O-methyl)-D-glucosyl esters were found to stimulate insulin release in pancreatic islets and the isolated perfused pancreas. The 6-O-D-glucosyl ester also stimulated insulin release after intravenous administration to anaesthetized rats. These findings suggest that the undersirable generation of methanol from the methyl esters of succinic acid could eventually be avoided by using other esters of this dicarboxylic acid, whilst keeping the benefit of their insulinotropic action.

Animals↗
PubMedDate not supplied

Nephrotoxicity of cyclosporine A in the rat. I. Specific intrarenal zonation of reduced succinate dehydrogenase activity.

The intranephronal distribution pattern of the activity of succinate dehydrogenase, a marker enzyme of mitochondrial inner membranes, was examined by histochemical investigation in the kidneys of 27 male Sprague-Dawley rats. The animals received cyclosporine A per os (15, 30 or 50 mg/kg.day) for 12 or 24 days. Six animals of the latter group remained untreated for a further 24 days. Five rats treated orally with 30 mg/kg.day olive oil served as controls. The kidneys of 2 normal male Sprague-Dawley rats were examined for comparison. Cyclosporine A reversibly induced a characteristic pattern of nephron segments with various degrees of reduced succinate dehydrogenase activity: in the proximal and distal tubules of subcapsular areas of the cortical labyrinth, of the medullary rays, and of the outer stripe of the outer medulla. The remaining areas contained tubules with normal succinate dehydrogenase activity, as confirmed by microphotometrical measurement. The number of these tubules appeared to be decreased under higher doses of cyclosporine A, irrespective of the duration of treatment. The finding of heterogeneous affection of tubular mitochondrial cristae membranes reflects direct tubulotoxicity of cyclosporine A.

Animals↗
PubMed1994

Study of the succinate dehydrogenase activation in permeabilized mitochondria through the Ca(2+)-stimulated phospholipase A2.

The development of a mitochondrial membrane permeability triggered by the Ca(2+)-stimulation of PLA2 (phospholipase A2; EC 3.1.1.4.) and based on swelling, polyunsaturated fatty acids release and calcium influx, induced the activation of SDH (succinate dehydrogenase; EC 1.3.9.9.) without damaging mitochondria structures. The activity of SDH increased within the length of permeabilization treatment before reaching a plateau. The study of Km and Vm showed that the affinity of SDH for succinate and the maximal velocity were increased. Based on these results, the change of SDH activity triggered under these conditions could be explained by a substrate activation of SDH taking account that the succinate content was significantly enhanced.

Animals↗
PubMed1975

Adenine nucleotide synthesis and growth rate of the adenyl succinate lyase mutant of Bacillus anthracis.

After mutations affecting the de novo adenine nucleotide synthesis in Bacillus anthracis, the salvage pathway failed to ensure growth at the prototroph level. In sonicated suspensions of adenyl succinate lyase deficient B. anthracis mutant, in the presence of exogenous 5-phosphoribosyl-1-pyrophosphate (PRPP), part of the labelled adenine was incorporated into adenine nucleotides. Addition of PRPP to cultures of adenyl succinate lyase and adenyl succinate synthetase mutants failed to promote growth. Both kinds of auxotroph showed in vitro a reduced growth rate as compared to the prototrophic strain.

Adenine↗
PubMed1994

Isolation and characterization of the Saccharomyces cerevisiae SDH4 gene encoding a membrane anchor subunit of succinate dehydrogenase.

Succinate dehydrogenase (EC 1.3.99.1) is an intrinsic bacterial or inner mitochondrial membrane protein that catalyses the oxidation of succinate and donates electrons to the respiratory chain via quinone acceptors. It is a heterotetramer composed of a flavoprotein, an iron-sulfur, and two hydrophobic subunits. We purified succinate dehydrogenase by blue native gel electrophoresis, determined the amino-terminal sequence of the Sdh4p subunit and used this information to clone the SDH4 gene. It encodes a precursor protein of 181 amino acids that is converted to the 150-amino acid mature Sdh4p protein with a mass of 16,638 Da. Hydrophobicity analysis predicts that Sdh4p forms three transmembrane alpha-helices. We have constructed an SDH4 mutant by targeted gene disruption; it retains the ability to grow on rich glycerol medium. Western blot analysis of SDH4 disruption mutant membrane fractions indicates that membrane attachment of the flavoprotein and iron-sulfur subunits is impaired but not abolished. This membrane-bound enzyme is able to reduce ubiquinone, although less efficiently than the wild-type enzyme. These findings indicate that Sdh4p contributes both to the membrane attachment of the catalytic flavoprotein and iron-sulfur subunits and to electron transfer to ubiquinone.

Amino Acid Sequence↗
PubMed1977

Effect of membrane environment on succinate dehydrogenase activity.

The turnover number of succinate dehydrogenase from mammalian heart determined by the spectrophotometric phenazine methosulfate assay, after complete activation, is approximately 21,000 mol of succinate oxidized/min/mol of histidyl flavin at 38 degrees in relatively intact inner membrane preparations and mitochondria. Reconstitutively active soluble preparations, extracted anaerobically in the presence of succinate from inner membrane preparations show turnover numbers of 11,500 to 14,500 and a significantly lower apparent Km for phenazine methosulfate than the parent particles. The decline of both the turnover number and of the Km occurs during the brief period when the enzyme is detached from the membrane. The observed values represent the activities in the soluble extract of both the reconstitutively active and reconstitutively inactive enzyme. The latter may be from 10 to 40% even in the most carefully prepared enzyme; it has a lower turnover number in the phenazine methosulfate assay than the average for the solution and is devoid of catalytic activity in the "low Km" ferricyanide assay (Vinogradov, A. D., Ackrell, B.A.C., and Singer, T.P. (1975) Biochem. Biophys. Res. Commun. 67, 803-809). The reconstitutively active form of the soluble enzyme has a turnover number of at least 15,000 and an equal activity in the low Km ferricyamide assay. When recombined with the membrane the total activity of the enzyme is increased by over 60% and it regains the original turnover number, Km for phenazine methosulfate, and sensitivity of the phenazine methosulfate reductase activity to thenoyltrifluoroacetone, carboxamides, and cyanide. It appears, therefore, that the membrane environment or some component of it exerts a positive modulating influence on the enzyme even in the fully activated state. In certain particulate sources (Keilin-Hartree preparations, Complex II) the enzyme shows lower turnover numbers (11,000 to 12,500) than in more intact inner membranes. This seems to be due to inactivation in the course of preparation and, in the case of Complex II, in part also to loss of the normal membrane environment or of a membrane component, possibly Q-10, during isolation.

Animals↗
PubMed1993

[Experimental and clinical study in vitro chemosensitivity test for succinate dehydrogenase inhibition test].

The usefulness and problems in the succinate dehydrogenase inhibition (SDI) test as an in vivo chemosensitivity test were reviewed and discussed. SDI test is based on the correlation of succinate dehydrogenase activity with cell viability. The optimal condition of SDI test were evaluated with respect to concentration of anticancer drugs, incubation time, effect of sodium succinate on formazan production and enzymatic disaggregation of solid tumors. Analysis of the chemosensitivity of clinical tumors revealed that the origin of tumor, histological differentiation, DNA distribution patterns, estrogen receptor status in breast cancer, and difference of primary and metastatic lesions were critical for determining the chemosensitivity of tumor tissues. Correlation between in vitro sensitivity in the SDI test and in vivo clinical results of chemotherapy was evaluated. Since SDI test reflects cell viability and is a simple, rapid and inexpensive methods, it is appropriate both for clinical chemosensitivity testing and for the screening of anticancer drugs.

Colonic Neoplasms↗
PubMed1997

In vivo stimulation of insulin release by the monoethyl, monopropyl, monoisopropyl, monoallyl and diallyl esters of succinic acid.

The methyl esters of succinic acid are potent insulin secretagogues, currently under investigation as possible tools in the treatment of non-insulin-dependent diabetes. The in vivo administration of these esters may result, however, in the undesirable generation of methanol. The present study reveals that other esters of succinic acid, such as the monoethyl, monopropyl, monoisopropyl, monoallyl and diallyl esters, stimulate insulin release when administered intravenously in a dose of 2 mumol/g body weight to anaesthetized fed rats. This indicates that several succinic acid esters, that are not susceptible to lead, through their intracellular hydrolysis, to the production of methanol remain efficient in vivo as insulin secretagogues.

Animals↗
PubMed1976

[Effect of succinic semialdehyde on nitrogen metabolism of animal brain tissue during hypoxia].

In examining the content of free ammonia, glutamine and some free amino acid s in the brain tissue of mice under normal conditions, in hypoxia and under the effect of succinic acidsemialdehyde, in hypoxia there was revealed a marked increase in comparison with the normal conditions) of the content of free ammonia, and alpha-alanine, a reduction of glutamine; there was also a slight elevation in the content of gamma aminobutyric acid and no changes in glutamic and asparagic acid content. In case of pretreatment with succinic acid semialdehyde the content of free ammonia, glutamine and alpha-alanine in hypoxia approached the normal value. One of the possible mechanisms of the antihypoxic effect of succinic acid semialdehyde was transformation of this compound as a results of which there occurred synthesis of glutamic acid and glutamine leading to detoxication of free ammonia accumulating in the brain tissue in hypoxia.

Alanine↗
PubMedDate not supplied

[Dual reciprocal regulation of the succinate oxidation system in heart and liver mitochondria in pathological conditions].

The phenomenon of the dual reciprocal regulation of succinate dependent 2H+/Ca2+ exchange was studied in heart and liver mitochondria of experimental animals (allogenic heart transplantation in rat; myocardium infarction in rabbits; pulmonary arteria coarctation in dogs) and in liver bioptates from patients with stomach ulcer. Under pathology two coupled but opposite changes (simultaneous activation and inhibition) in succinate dependent Ca2+ transport occur. The inhibition of Ca2+ transport was detected by its elimination with glutamate, being mostly pronounced after cycle of ADP phosphorylation added to suspension of mitochondria. The treatment of animal with 2-oxoglutarate abolished this inhibition. This was not observed in healthy animals. The described phenomenon can prevent hyperactivation of succinate oxidation under strong pathological (distress) influences.

Animals↗