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Biomedical subjects

K Takeshige

Publications and source records attributed to K Takeshige.

At least 145 records · Page 8Linked to original sources
PubMed1980

NADH- and NADPH-dependent lipid peroxidation in bovine heart submitochondrial particles. Dependence on the rate of electron flow in the respiratory chain and an antioxidant role of ubiquinol.

Malondialdehyde formations by bovine heart submitochondrial particles supported by NADH or NADPH in the presence of ADP and FeCl3 was studied. The NADH-dependent reaction was maximal at very low rate of electron input from NADH to the respiratory chain and it decreased when the rate became high. The reaction was stimulated by rotenone and inhibited by antimycin A when the input was fast, whereas it was not affected by the inhibitors when the input was slow. The input rate of the electrons from NADPH was also so low that the reaction supported by NADPH was not affected by the inhibitors. Most of the endogenous ubiquinone in the particles treated with antimycin A was reduced by NADH even in the presence of ADP-Fe3+ chelate, but uniquinone was not reduced by NADPH when ADP-Fe3+ was present. Succinate strongly inhibited both NADH- and NADPH-dependent lipid peroxidation. The inhibition was abolished when uniquinone was removed from the particles, and it appeared again when uniquinone was reincorporated into the particles. Reduced uniquinone-2 also inhibited the peroxidation, but duroquinol, which reduces cytochrome b without reducing endogenous uniquinone, did not. Thus the malondialdehyde formation appeared to be inversely related to the extent of the reduction of endogenous uniquinone. These observations suggest that both NADH- and NADPH-dependent liquid-peroxidation reactions are closely related to the respiratory chain and that the peroxidation is controlled by the concentration of reduced ubiquinone.

Animals↗
PubMed1980

Lipid peroxidation and the reduction of ADP-Fe3+ chelate by NADH-ubiquinone reductase preparation from bovine heart mitochondria.

The NADH-ubiquinone reductase preparation (Complex I) of bovine hart mitochondria catalysed in the presence of reduced coenzymes and ADP-Fe3+ the lipid peroxidation of liposomes prepared from mitochondrial lipids. The apparent Km values for the coenzymes and the optimal pH of the reactions agreed well with those of the lipid peroxidation of the submitochondrial particles treated with rotenone. On assay of the reduction of ADP-Fe3+ chelate by the reduction of cytochrome c in the presence of superoxide dismutase and antimycin A or by the oxidation of reduced coenzymes, the reactions were not affected by rotenone but were inhibited by thiol-group inhibitors. The properties of the ADP-Fe3+ reductase activity were highly consistent with those of the lipid-peroxidation reaction. These observations suggest that electrons from reduced coenzymes are transferred to ADP-Fe3+ chelate from a component between a mercurial-sensitive site and the rotenone-sensitive one of the NADH dehydrogenase and that the reduction of ADP-Fe3+ chelate by the NADH dehydrogenase is an essential step in the lipid peroxidation.

Adenosine Diphosphate↗
PubMed1979

NADH- and NADPH-dependent formation of superoxide anions by bovine heart submitochondrial particles and NADH-ubiquinone reductase preparation.

1. Both NADH and NADPH supported the oxidation of adrenaline to adrenochrome in bovine heart submitochondrial particles. The reaction was completely inhibited in the presence of superoxide dismutase, suggesting that superoxide anions (O(2) (-)) are responsible for the oxidation. The optimal pH of the reaction with NADPH was at pH7.5, whereas that with NADH was at pH9.0. The reaction was inhibited by treatment of the preparation with p-hydroxymercuribenzoate and stimulated by treatment with rotenone. Antimycin A and cyanide stimulated the reaction to the same extent as rotenone. The NADPH-dependent reaction was inhibited by inorganic salts at high concentrations, whereas the NADH-dependent reaction was stimulated. 2. Production of O(2) (-) by NADH-ubiquinone reductase preparation (Complex I) with NADH or NADPH as an electron donor was assayed by measuring the formation of adrenochrome or the reduction of acetylated cytochrome c which does not react with the respiratory-chain components. p-Hydroxymercuribenzoate inhibited the reaction and rotenone stimulated the reaction. The effects of pH and inorganic salts at high concentrations on the NADH- and NADPH-dependent reactions of Complex I were essentially similar to those on the reactions of submitochondrial particles. 3. These findings suggest that a region between a mercurialsensitive site and the rotenone-sensitive site of the respiratory-chain NADH dehydrogenase is largely responsible for the NADH- and NADPH-dependent O(2) (-) production by the mitochondrial inner membranes.

Animals↗
PubMed1979

Simple and rapid method for the diagnosis of chronic granulomatous disease, measuring hydrogen peroxide and superoxide anions released from leukocytes in whole blood.

A simple quantitative method to measure release of hydrogen peroxide and superoxide anions from leukocytes using less than 10 microliter blood is described. Whole blood instead of a leukocyte suspension was used. The release of hydrogen peroxide was measured fluorometrically by adding a blood sample to an assay mixture containing homovanillic acid, peroxidase and azide. The release of superoxide anions was measured spectrophotometrically with a dual wavelength spectrophotometer by adding a blood sample to an assay mixture containing cytochrome C. The normal values of the releasing activities are given.

Concanavalin A↗
PubMed1976

Mitochondrial adenosine triphosphatase from yeast, Saccharomyces cerevisiae. Purification, subunit structure and kinetics.

1. A procedure for the purification of ATPase extracted by chloroform from baker's yeast (Saccharomyces cerevisiae) is reported. The yield based on submitochondrial particles was 55% and the purification was 100-fold. The isolated complex was homogenous as assessed by gel filtration, ion-exchange chromatography, sedimentation in sucrose gradient and in the analytical ultracentrifuge. The molecular weight determined by gel filtration was 400000 +/- 20000. Ultracentrifugation yielded s020,w = 12.50 +/- 0.13 S and the laser light scattering study gave a diffusion coeficient of D20w - 2.92 X 10(-7) cm2 s-1. The amino acid composition as well as absorption, fluorescence, and circular dichroism spectra, from which the helicity of 39% was evaluated, are given. 2. On polyacrylamide gel electrophoresis in the presence of sodium dodecylsulfate, six components with molecular weights of 58500(alpha), 55000 (beta), 42000, 34000 (gamma), 10000(delta), and 8600 (epsilon) were observed with a stoichiometry of 3:3:1:1:1:1. The amino acid composition is given for alpha + beta and gamma as well as delta and epsilon components. 3. The maximum specific activity of the enzyme was 200 U/mg under the optimum conditions. The enzyme was inactivated by incubation at 0 degrees C and strongly inhibited by the antibiotic Dio-9 but not by oligomycin and N, N'-dicyclohexyl-carbodiimide. The effects of kinetic parameters and anions on the enzyme are reported. Two active sites for Mg-ATP with Km values of 0.045mM and 0.37mM and a single activie site for Mg-ITP with Km = 0.179mM were found. A study of the temperature dependence of the maximum activity revealed a straight line in the Arrhenius plots with an activation energy of 11.0 kcal/mol (= 46 kH/mol).

Adenosine Triphosphatases↗
PubMed1976

The late results of terminal esophagoproximal gastrectomy (TEPG) with intensive devascularization and splenectomy for bleeding esophageal varices in cirrhosis.

The operative procedure of terminal esophagoproximal gastrectomy (TEPG) with extensive esophagogastric devascularization and splenectomy is described in detail and its rationale is discussed. Late results of this operation performed therapeutically on 64 patients with posthepatitic cirrhosis revealed that (1) operative mortality rate (death within a month) was 11%, mostly being contributed by poor-risk patients; (2) over-all survival was 65% at 5 years and 59% at 10 years; (3) gastrointestinal bleeding recurred in nine patients, five of whom had major and four minor hemorrhages; (4) portasystemic encephalopathy was seen frequently after shunts had never occurred, and the hepatic encephalopathy was only a sequel of major gastrointestinal bleeding or a manifestation of terminal-stage liver insufficiency; and (5) ascites was not a major clinical problem after this operation; mild esophagitis was an occasional complication.

Esophageal and Gastric Varices↗
PubMed1975

Metabolic pattern of polymorphonuclear leucocytes induced by trypsin-digested microsomes.

The addition of trypsin [EC 3.4.21.4]-digested liver microsimes induced cyanideinsensitive respiration in guinea pig polymorphonuclear leucocytes with concomitant acceleration of the hexose monophosphate oxidative pathway. The respiration was insensitive to inhibitors of mitochondrial respiration but sensitive to glycolytic inhibitors. These metabolic alterations are similar to those associated with phagocytosis, though the digested mocrosomes were apparently not taken up by the cells and prpbably trigger the netabolic changes by interaction with the cellular membrane. Intact microsomes or microsomes treated with chymotrypsin [EC 3.4.21.1], bacterial proteinase, ribonuclease [EC 3.1.4.22], or neuraminidase [EC 3.2.1.18] could not induce such respiration.

Animals↗
PubMed1975

Effect of cyclic nucleotides on the cyanide-insensitive respiration of polymorphonuclear leucocytes.

The effects of N6,O2'-dibutyryladenosine 3',5'-monophosphate (Bu2-cyclic AMP) and N2,O2'-dibutyrylguanosine 3',5'-monophosphate (Bu2-cyclic GMP) on the cyanide-insensitive respiration of guinea pig peritoneal exudate polymorphonuclear leucocytes were studied. Bu2-cyclic AMP inhibited the respiration induced both by phagocytosis of E. coli and by the interaction with trypsin-digested rat liver microsomes. The addition of theophylline gave rise to an inhibitory pattern similar to that with Bu2-cyclic AMP against both the respirations induced. On the other hand, Bu2-cyclic GMP did not affect the respiration induced by phagocytosis whereas it inhibited the respiration induced by the addition of myristic acid was inhibited by Bu2-cyclic AMP, which was similar to that with E. coli. The respiration induced by methylene blue was inhibited neither by Bu2-cyclic AMP nor by Bu2-cyclic GMP. These observations suggest that the cyanide-insensitive respiration of polymorphonuclear leucocytes may be classified into at least three types from the inhibitory pattern of cyclic AMP and cyclic GMP.

Animals↗
PubMed1975

Reduced nicotinamide adenine dinucleotide phosphate-dependent lipid peroxidation by beef heart submitochondrial particles.

Electron transport particles (ETP) prepared from beef heart mitochondria formed malondialdehyde by NADPH-dependent lipid peroixidation in the presence of ferric ions and ADP or ATP. The reaction was inhibited by MnCl2, EDTA, or radical scavengers, but was not inhibited by p-hydroxymercuribenzoate (PHMB) or respiratory chain inhibitors. The oxidation of NADPH and oxygen consumption by ETP were activated by the addition of ferric ions and APT, and inhibited by inhibitors of lipid peroxidation. This peroxidation system was apparently different from those of liver microsomes and mitochondria as regards the effect of PHMB, optimal pH and the concentration of NADPH for half-maximal reaction velocity.

Adenosine Diphosphate↗