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Biomedical subjects

K Kakinuma

Publications and source records attributed to K Kakinuma.

At least 109 records · Page 6Linked to original sources
PubMed1982

Subcellular localization of O2- generating enzyme in guinea pig polymorphonuclear leukocytes; fractionation of subcellular particles by using a Percoll density gradient.

An iso-osmotic Percoll density gradient was applied to determine the subcellular localization of the O2- generating enzyme, NADPH oxidase, in guinea pig polymorphonuclear leukocytes (PMN). [14C]Myristate (MA) was employed as a metabolic stimulant in order to clarify whether the myristate binding site on PMN membrane was identical with the O2- generating site. The distribution pattern of the O2- generating activity of MA-activated PMN was compared with that of unactivated PMN in parallel experiments to find fractions showing an enhanced O2- generating activity (i.e., above the background values due to O2-generation by other electron-transport systems). We observed very high O2- generating activity concentrated in a single peak with MA-activated PMN but little activity was seen with unactivated PMN in the Percoll density gradient. The O2- generating activity of MA-activated PMN was consistently associated with 5'-nucleotidase activity as a membrane marker enzyme, but was not associated with lysosomal marker enzymes such as myeloper-oxidase and lysozyme. O2- generating and 5'-nucleotidase activities in the peak fraction of MA-activated PMN were increased to about six and four times those of whole cells in terms of specific activity, respectively. These results indicate that the O2- generating enzyme is located on PMN plasma membrane. Furthermore, [14C]myristate-binding activity was mainly found in the peak fraction containing O2 - generating enzyme. This suggests that [14C]myristate binds to plasma membrane, and the O2 - generating enzyme may thus be activated.

5'-Nucleotidase↗
PubMed1982

Biosynthesis of vineomycins A1 and B2.

Biosynthetic studies of the antibacterial and antitumor antibiotics vineomycins A1 (1) and B2 (2), produced by Streptomyces matensis subsp. vineus, were carried out by labeling experiments with [1-13C]- and [1,2-18C2]sodium acetate followed by 18C NMR spectroscopy. The results show that the benz[a]anthraquinone chromophore of 1 is derived from a decacetate metabolite with decarboxylation at the carboxyl end and that 2 is formed via C-C bond cleavage of 1. Isolation of rabelomycin from the fermentation broth of the same strain suggests a close biosynthetic relationship among the simple benz[a]anthraquinone antibiotics such as rabelomycin, tetrangomycin, aquayamycin, a C-glycosylated benz[a]anthraquinone, and vineomycins. These biosynthetic data prompted us to reconsider the previously published structure of the antibiotic SS-228Y, which has not been revised.

Anthraquinones↗
PubMed1982

Effects of neuraminidase on O2 consumption and release of O2 and H2O2 from phagocytosing human polymorphonuclear leukocytes.

Neuraminidase type X (NMD-type-X, Sigma Chemical Co., St. Louis, Mo.), which is obtained from a further purification of neuraminidase type V (NMD-type-V, Sigma), markedly enhanced the release of O2- and H2O2 from phagocytosing human polymorphonuclear leukocytes (PMN). In contrast, O2 consumption by NMD-type-X-treated PMN was identical to that of untreated PMN. Morphological observations suggested that the enhancement of O2- and H2O2 release was caused by excessive release of the oxygen metabolites into the extracellular medium from incompletely formed phagocytic vacuoles as was observed with cytochalasin-B-treated cells. Our observations are in contrast to the previous reports of Tsan et al. that showed complete inhibition of both O2- and H2O2 release from phagocytosing PMN by the treatment with NMD-type-V.

Cell-Free System↗
PubMed1980

Comparative studies on alveolar macrophages and polymorphonuclear leukocytes. I. H2O2 and O2- generation by rabbit alveolar macrophages.

The oxidative metabolism of rabbit alveolar macrophages (A-MO) was compared with that of rabbit polymorphonuclear leukocytes (PMN) with respect to H2O2 generation by intact cells or subcellular fractions. Rabbit PMN exhibited an increase in the oxygen uptake and a marked release of H2O2 upon addition of heat-killed E. coli in the presence and absence of opsonin. However, rabbit A-MO exhibited an increase in the oxygen uptake upon addition of E. coli only in the presence of anti-E. coli serum as an opsonin, whereas a very small amount of H2O2 release was observed during ingestion of the opsonized E. coli. The generation of O2- and H2O2 by a granule-rich fraction isolated from phagocytosing PMN was larger than that by a similar fraction isolated from resting PMN. However, there was no significant difference in O2- and H2O2 generation by the granule fractions between phagocytosing and resting A-MO in the presence of either NADH or NADPH. In contrast to the granule fraction of rabbit PMN, the O2- and H2O2 generating activities in the A-MO granule fraction were higher in the presence of NADH than in the presence of NADPH. The rates of NADH and NADPH oxidation by both A-MO and PMN granule fractions were measured with and without addition of Mn2+ to the assay medium. The effect of Mn2+ on the NAD(P)H oxidase was found to differ between rabbit A-MO and PMN.

Animals↗
PubMed1980

Comparative studies on alveolar macrophages and polymorphonuclear leukocytes. II. The ability of guinea pig alveolar macrophages to produce H2O2.

Guinea pig alveolar macrophages (A-M0) were studied with respect ot the phagocytic metabolism: the respiratory burst and its KCN sensitivity, the ability to generate H2O2, and myeloperoxidase (MPO) activity. Only fifty percent of the O2 uptake by A-M0 samples during phagocytosis was inhibited by the addition of 1 mK KCN. Guinea pig A-M0 released H2O2 amounting to 7.7 and 12.5 nmol/min/10(7) cells upon addition of E. coli in the absence and presence of anti-E. coli antibody, respectively. Myristic acid, an effective membrane activator, induced a marked release of H2O2 amounting to 16.1 nmol/min/10(7) cells. We observed a high MPO activity in some alveolar lavage cells which contained a large number of polymorphonuclear leukocytes (PMN), but none at all in preparations containing fewer PMN. The MPO activity detected did not seem to be due to A-M0, but to the PMN contained in the preparations.

Animals↗
PubMed1980

Comparative studies on alveolar macrophages and polymorphonuclear leukocytes. III. Difference spectra of their cellular and subcellular fractions.

The respiratory pigments of rabbit polymorphonuclear leukocytes (PMN) and alveolar macrophages (A-MO) were compared in a spectrophotometric study conducted at liquid nitrogen temperature. In the difference spectra of the KCN-treated minus the untreated states and of the reduced minus the oxidized states, the cellular and granular fractions of PMN showed sharp absorption maxima identical with the absorption bands of myeloperoxidase (MPO). Even though A-MO revealed some guaiacol-peroxidation activity, the difference spectra of cellular and subcellular A-MO fractions did not show an MPO spectrum. The enzyme catalyzing the guaiacol peroxidation by A-MO appears to be an enzyme other than the MPO found in PMN. Despite the absence of the MPO spectrum, the difference spectra of A-MO granules when measured with KCN, dithionite, and succinate showed characteristic absorption bands of mitochondrial cytochromes, in contrast to the difference spectra of PMN, which showed far smaller cytochrome absorption bands. The results obtained suggest that the phagocytic metabolism of rabbit A-MO depends on mitochondrial respiration for its energy supply.

Animals↗
PubMed1980

H2O2 release from filtration leukapheresis-procured leukocytes.

Filtration leukapheresis-procured leukocytes (FL-leukocytes), which were collected by the elution of filtration columns with vigorous tapping, released a certain amount of H2O2 even in the absence of any phagocytic stimuli. Furthermore, FL-leukocytes, eluted with either gentle or vigorous tapping, exhibited a marked release of H2O2 during phagocytosis. The myeloperoxidase (MPO) activity of FL-leukocytes was lower than that of leukocytes collected by the dextran sedimentation method (DS-leukocytes). The data suggest that the release of both H2O2 and MPO from FL-leukocytes may be related to adverse transfusion reactions and abnormal post-transfusion kinetics of FL-leukocytes due to their toxic effects on living cells.

Horseradish Peroxidase↗
PubMed1979

Formation of a TBA reaction product from crown ether in the presence of KO2.

Potassium superoxide (KO2), which can be dissolved in dimethyl sulfoxide containing crown ether, has been used as a source of O2-. for superoxide reaction systems. We have found that crown ether reacts with thiobarbituric acid (TBA) in the presence of KO2 to form a red pigment, which is a well-known reaction product of lipoperoxide.

Dimethyl Sulfoxide↗
PubMed1979

A determination of H2O2 release by the treatment of human blood polymorphonuclear leukocytes with myristate.

Free H2O2 released from human blood leukocytes during phagocytosis into the extracellular medium was highly reactive with the ferric form of HRP, forming an enzyme-substrate complex which was identical to HRP-H2O2 compound II. The formation of HRP-H2O2 compound II was employed for assaying the rates of H2O2 release by leukocytes upon addition of bacteria or myristate. The treatment of normal human blood leukocytes with myristate resulted in a marked stimulation of H2O2 release compared to phagocytizing cells. The activity of H2O2 release in response to myristate was found to be deficient in the leukocytes of two patients with chronic granulomatous disease. This assay method with myristate supplementation is so sensitive and specific that it should be useful for the diagnosis of chronic granulomatous disease.

Adult↗
PubMed1978

Effects of fatty acids on superoxide radical generation in leukocytes.

Acetylated ferricytochrome c was employed for the detection of superoxide radicals (O-2) generated both in intact cells and in subcellular fractions of leukocytes. Certain saturated fatty acids, myristate in particular, induced the production of O-2 in leukocytes, suggesting a correlation between the formation of O-2 and the hydrophobic interaction of fatty acids with the leukocyte plasma membrane. As compared with O-2 radical generation from phagocytizing leukocytes a greater stimulation of O-2 formation was observed in cells in which myristate was added. The enhanced activity which generated O-2 in the cell-free system was located in a particulate fraction but not in the cytosol. The rate of O-2 generation in the particulate fraction was higher in the presence of NADPH than in the presence of NADH. The effects of reagents such as KCN, 2,4-dichlorophenol and aminotriazole on the O-2 generation in this fraction are examined and the nature of the O-2 generating system is discussed.

Amitrole↗
PubMed1977

Spectrophotometric studies on NAD(P)H oxidase of leukocytes. 1. The relationship between granule-NAD(P)H oxidase and myeloperoxidase.

The NAD(P)H oxidase located in granules from resting leukocytes seems to be identical with myeloperoxidase on the basis of the following results. Spectral changes representing the difference between granules with and without NAD(P)H under various conditions represented the formation of compound III of myeloperoxidase, corresponding to the oxidation of NAD(P)H. The KCN difference spectrum of granules from both resting and phagocytizing leukocytes was in agreement with the KCN difference spectrum of myeloperoxidase. The affinity of KCN for myeloperoxidase was the same in both resting and phagocytizing leukocytes. The KCN-sensitive portion of NAD(P)H oxidase of granules from phagocytizing leukocytes seems to be identical with isolated myeloperoxidase and the myeloperoxidase of resting leukocytes. The KCN-insensitive oxidation of NAD(P)H by granules from phagocytizing leukocytes has not been found to be identical with myeloperoxidase.

Animals↗
PubMed1976

Studies on the mechanism of metabolic stimulation in polymorphonuclear leukocytes during phagocytosis. Activators and inhibitors of the granule bound NADPH oxidase.

The effects of several known inhibitors and activators of peroxidase-catalyzed reactions have been studied on the NADPH oxidase activity of granules isolated from polymorphonuclear leukocytes at rest or during phagocytosis. Redogenic substances, such as ascorbate or hydroquinone, and superoxide dismutase, which are known to inhibit peroxidase-catalyzed reactions, also inhibited the NADPH oxidase activity of granules. Oxidogenic substances, such as guaiacol or resorcinol, and manganese, which are known to stimulate peroxidase-catalyzed reactions, also activated the NADPH oxidase activity of granules. Cyanide, an inhibitor of peroxidase-catalyzed reactions, inhibited the NADPH oxidase activity of granules isolated from resting leukocytes but only slightly affected that of granules isolated from phagocytosing cells, as previously reported. A list of the properties of the NADPH oxidase activity of granules and of peroxidase oxidase activity is given. The arguments in favor of and those against a possible identity of the two activities are discussed.

Animals↗
PubMed1976

Lack of cytochalasin E-induced superoxide release by polymorphonuclear leucocytes of patients with chronic granulomatous disease: a new diagnostic test.

Reduction of exogenous cytochrome c was induced by the treatment of human polymorphonuclear leucocytes with cytochalasin E. The reduction was completely inhibited by superoxide, dismutase, indicating that superoxide anions were released from the cells. The leucocytes from two patients with chronic granulomatous disease did not show the release reaction that should have been brought on by the treatment. The cytochalasin-induced reduction of exogenous cytochrome c by polymorphonuclear leucocytes is so specific and sensitive that it seems to be useful for diagnosis of chronic granulomatous disease.

Adult↗