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71.
Takehito Kemuriyama Hiroyuki Ohta Yoshiaki Sato Satoshi Maruyama Megumi Tandai-Hiruma Kazuo Kato Yasuhiro Nishida 《Bio Systems》2010,101(2):144-147
To assess sympathetic variability in chronic heart failure (CHF), we evaluated a distribution of inter-spike intervals (ISIs) in renal sympathetic nerve activity (RSNA) in salt-sensitive hypertension-induced CHF (DSSH-CHF) rats. Dahl salt-sensitive rats were fed an 8% NaCl diet for 9 weeks to induce salt-sensitive hypertension-induced CHF. ISIs in RSNA were obtained from chronically instrumented conscious rats, and counts (frequency) and ranks of ISIs in RSNA were plotted with a histogram. We found that ISIs in RSNA followed a power-law distribution in rats, and the power-law distribution of ISIs for RSNA in DSSH-CHF rats was significantly different from that in normal rats. These results indicated that sympathetic variability may be significantly different between salt-sensitive hypertension-induced CHF and healthy individuals, which suggests that sympathetic variability may be used to predict abnormality of the sympathetic regulatory system. 相似文献
72.
73.
Miwako Matsuki-Fukushima Junko Fujita-Yoshigaki Masataka Murakami Osamu Katsumata-Kato Megumi Yokoyama Hiroshi Sugiya 《The Journal of membrane biology》2013,246(3):209-214
In secretory granules and vesicles, membrane transporters have been predicted to permeate water molecules, ions and/or small solutes to swell the granules and promote membrane fusion. We have previously demonstrated that aquaporin-6 (AQP6), a water channel protein, which permeates anions, is localized in rat parotid secretory granules (Matsuki-Fukushima et al., Cell Tissue Res 332:73–80, 2008). Because the localization of AQP6 in other organs is restricted to cytosolic vesicles, the native function or functions of AQP6 in vivo has not been well determined. To characterize the channel property in granule membranes, the solute permeation-induced lysis of purified secretory granules is a useful marker. To analyze the role of AQP6 in secretory granule membranes, we used Hg2+, which is known to activate AQP6, and investigated the characteristics of solute permeability in rat parotid secretory granule lysis induced by Hg2+ (Hg lysis). The kinetics of osmotic secretory granule lysis in an iso-osmotic KCl solution was monitored by the decay of optical density at 540 nm using a spectrophotometer. Osmotic secretory granule lysis was markedly facilitated in the presence of 0.5–2.0 μM Hg2+, concentrations that activate AQP6. The Hg lysis was completely blocked by β-mercaptoethanol which disrupts Hg2+-binding, or by removal of chloride ions from the reaction medium. An anion channel blocker, DIDS, which does not affect AQP6, discriminated between DIDS-insensitive and sensitive components in Hg lysis. These results suggest that Hg lysis is required for anion permeability through the protein transporter. Hg lysis depended on anion conductance with a sequence of NO3 ? > Br? > I? > Cl? and was facilitated by acidic pH. The anion selectivity for NO3 ? and the acidic pH sensitivity were similar to the channel properties of AQP6. Taken together, it is likely that AQP6 permeates halide group anions as a Hg2+-sensitive anion channel in rat parotid secretory granules. 相似文献
74.
The Extracellular A-loop of Dual Oxidases Affects the Specificity of Reactive Oxygen Species Release
Takehiko Ueyama Megumi Sakuma Yuzuru Ninoyu Takeshi Hamada Corinne Dupuy Miklós Geiszt Thomas L. Leto Naoaki Saito 《The Journal of biological chemistry》2015,290(10):6495-6506
NADPH oxidase (Nox) family proteins produce superoxide (O2⨪) directly by transferring an electron to molecular oxygen. Dual oxidases (Duoxes) also produce an O2⨪ intermediate, although the final species secreted by mature Duoxes is H2O2, suggesting that intramolecular O2⨪ dismutation or other mechanisms contribute to H2O2 release. We explored the structural determinants affecting reactive oxygen species formation by Duox enzymes. Duox2 showed O2⨪ leakage when mismatched with Duox activator 1 (DuoxA1). Duox2 released O2⨪ even in correctly matched combinations, including Duox2 + DuoxA2 and Duox2 + N-terminally tagged DuoxA2 regardless of the type or number of tags. Conversely, Duox1 did not release O2⨪ in any combination. Chimeric Duox2 possessing the A-loop of Duox1 showed no O2⨪ leakage; chimeric Duox1 possessing the A-loop of Duox2 released O2⨪. Moreover, Duox2 proteins possessing the A-loops of Nox1 or Nox5 co-expressed with DuoxA2 showed enhanced O2⨪ release, and Duox1 proteins possessing the A-loops of Nox1 or Nox5 co-expressed with DuoxA1 acquired O2⨪ leakage. Although we identified Duox1 A-loop residues (His1071, His1072, and Gly1074) important for reducing O2⨪ release, mutations of these residues to those of Duox2 failed to convert Duox1 to an O2⨪-releasing enzyme. Using immunoprecipitation and endoglycosidase H sensitivity assays, we found that the A-loop of Duoxes binds to DuoxA N termini, creating more stable, mature Duox-DuoxA complexes. In conclusion, the A-loops of both Duoxes support H2O2 production through interaction with corresponding activators, but complex formation between the Duox1 A-loop and DuoxA1 results in tighter control of H2O2 release by the enzyme complex. 相似文献
75.
Molecular Characterization of Photomixotrophic Tobacco Cells
Resistant to Protoporphyrinogen
Oxidase-Inhibiting
Herbicides 总被引:1,自引:1,他引:1 下载免费PDF全文
Naohide Watanabe Fang-Sik Che Megumi Iwano Seiji Takayama Takeshi Nakano Shigeo Yoshida Akira Isogai 《Plant physiology》1998,118(3):751-758
Peroxidizing herbicides inhibit protoporphyrinogen oxidase (Protox), the last enzyme of the common branch of the chlorophyll- and heme-synthesis pathways. There are two isoenzymes of Protox, one of which is located in the plastid and the other in the mitochondria. Sequence analysis of the cloned Protox cDNAs showed that the deduced amino acid sequences of plastidial and mitochondrial Protox in wild-type cells and in herbicide-resistant YZI-1S cells are the same. The level of plastidial Protox mRNA was the same in both wild-type and YZI-1S cells, whereas the level of mitochondrial Protox mRNA YZI-1S cells was up to 10 times the level of wild-type cells. Wild-type cells were observed by fluorescence microscopy to emit strong autofluorescence from chlorophyll. Only a weak fluorescence signal was observed from chlorophyll in YZI-1S cells grown in the Protox inhibitor N-(4-chloro-2-fluoro-5-propagyloxy)-phenyl-3,4,5,6-tetrahydrophthalimide. Staining with DiOC6 showed no visible difference in the number or strength of fluorescence between wild-type and YZI-1S mitochondria. Electron micrography of YZI-1S cells showed that, in contrast to wild-type cells, the chloroplasts of YZI-1S cells grown in the presence of N-(4-chloro-2-fluoro-5-propagyloxy)-phenyl-3,4,5,6-tetrahydrophthalimide exhibited no grana stacking. These results suggest that the herbicide resistance of YZI-1S cells is due to the overproduction of mitochondrial Protox. 相似文献
76.
Miura Y Hato M Shinohara Y Kuramoto H Furukawa J Kurogochi M Shimaoka H Tada M Nakanishi K Ozaki M Todo S Nishimura S 《Molecular & cellular proteomics : MCP》2008,7(2):370-377
Recent progress in mass spectrometry has led to new challenges in glycomics, including the development of rapid glycan enrichment techniques. A facile technique for exploration of a carbohydrate-related biomarker is important because proteomics research targets glycosylation, a posttranslational modification. Here we report an "all-in-one" protocol for high throughput clinical glycomics. This new technique integrates glycoblotting-based glycan enrichment onto the BlotGlycoABC bead, on-bead stabilization of sialic acids, and fluorescent labeling of oligosaccharides in a single workflow on a multiwell filter plate. The advantage of this protocol and MALDI-TOF MS was demonstrated through differentiation of serum N-glycan profiles of subjects with congenital disorders of glycosylation and hepatocellular carcinoma and healthy donors. The method also permitted total cellular glycomics analysis of human prostate cancer cells and normal human prostate epithelial cells. These results demonstrate the potentials of glycan enrichment/processing for biomarker discovery. 相似文献
77.
Masumi Hirabayashi Megumi Kato Ryosuke Kaneko Takahiro Hirabayashi Mitsuhiro Morita Shinichi Hochi 《Experimental Animals》2006,55(2):131-135
It was reported that recombinase-A protein (RecA)-coated exogenous DNA was more likely to be integrated into mouse, goat and pig genomes. The objective of this study was to investigate whether integration of exogenous DNA into the rat genome is improved by the recombinase-mediated DNA transfer. Pronuclear microinjection of RecA-coated EGFP or OAMB DNA resulted in a production efficiency of transgenic rats of 1.4-2.9%, comparable with 0.9-2.6% when non-coated control DNA was used. Intracytoplasmic injection of the sperm heads exposed to RecA-coated EGFP DNA did not produce any transgenic rats (0 vs. 0-2.8% in control groups). Thus, the recombinase-mediated DNA transfer contributed very little to the production of transgenic rats by means of pronuclear microinjection and intracytoplasmic sperm injection. 相似文献
78.
Megumi?IdaEmail author Itsurou?Ida Naoki?Wada Makoto?Sohmiya Masayuki?Tazawa Kenji?Shirakura 《BioPsychoSocial medicine》2013,7(1):18
Background
The efficacy of physical exercise as an augmentation to pharmacotherapy with antidepressants for depressive patients has been documented. However, to clarify the effectiveness of exercise in the treatment of depression, it is necessary to distinguish the effect of the exercise itself from the effect of group dynamics. Furthermore, an objective measurement for estimation of the effect is needed. Previous reports adopted a series of group exercises as the exercise intervention and mainly psychometric instruments for the measurement of effectiveness. Therefore, this clinical study was done to examine the effectiveness of a single session of individual exercise on depressive symptoms by assessing the change in saliva free cortisol level, which reflects hypothalamic-pituitary-adrenocortical axis function that is disturbed in depressive patients.Method
Eighteen medicated patients, who met the DSM-IV-TR criteria for major depressive disorder, were examined for the change in saliva free cortisol levels and the change in subjective depressive symptoms before and after pedaling a bicycle ergometer for fifteen minutes. Within a month after the exercise session, participants conducted a non-exercise control session, which was sitting quietly at the same time of day as the exercise session.Results
Depressed patients who participated in this study were in remission or in mild depressive state. However, they suffered chronic depression and had disturbed quality of life. The saliva free cortisol level and subjective depressive symptoms significantly decreased after the exercise session. Moreover, the changes in these variables were significantly, positively correlated. On the other hand, although the subjective depressive symptoms improved in the control session, the saliva free cortisol level did not change.Conclusion
For the first time in depressive patients, we were able to show a decrease in the saliva free cortisol level due to physical exercise, accompanied by the improvement of subjective depressive symptoms. This identified a possible influence of exercise on the hypothalamic-pituitary-adrenal axis in depression.These results suggest the utility of assessing the effect of physical exercise by saliva free cortisol level in depressive patients who suffer from bio-psycho-social disability.79.
Ikeda M Masumura K Sakamoto Y Wang B Nenoi M Sakuma K Hayata I Nohmi T 《Mutation research》2007,626(1-2):15-25
It is important to evaluate the health effects of low-dose-rate or low-dose radiation in combination with chemicals as humans are exposed to a variety of chemical agents. Here, we examined combined genotoxic effects of low-dose-rate radiation and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), the most carcinogenic tobacco-specific nitrosamine, in the lung of gpt delta transgenic mice. In this mouse model, base substitutions and deletions can be separately analyzed by gpt and Spi- selections, respectively. Female gpt delta mice were either treated with gamma-irradiation alone at a dose rate of 0.5, 1.0 or 1.5 mGy/h for 22 h/day for 31 days or combined with NNK treatments at a dose of 2 mg/mouse/day, i.p. for four consecutive days in the middle course of irradiation. In the gpt selection, the NNK treatments enhanced the mutation frequencies (MFs) significantly, but no obvious combined effects of gamma-irradiation were observable at any given radiation dose. In contrast, NNK treatments appeared to suppress the Spi- large deletions. In the Spi- selection, the MFs of deletions more than 1 kb in size increased in a dose-dependent manner. When NNK treatments were combined, the dose-response curve became bell-shaped where the MF at the highest radiation dose decreased substantially. These results suggest that NNK treatments may elicit an adaptive response that eliminates cells bearing radiation-induced double-strand breaks in DNA. Possible mechanisms underlying the combined genotoxicity of radiation and NNK are discussed, and the importance of evaluation of combined genotoxicity of more than one agent is emphasized. 相似文献
80.