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71.
Nomiyama T Igarashi Y Taka H Mineki R Uchida T Ogihara T Choi JB Uchino H Tanaka Y Maegawa H Kashiwagi A Murayama K Kawamori R Watada H 《Biochemical and biophysical research communications》2004,320(3):639-647
Inducible nitric oxide synthetase plays an essential role in insulin resistance induced by a high-fat diet. The reaction of nitric oxide with superoxide leads to the formation of peroxynitrite (ONOO-), which can modify several proteins. In this study, we investigated whether peroxynitrite impairs insulin-signalling pathway. Our experiments showed that 3-(4-morpholinyl)sydnonimine hydrochloride (SIN-1), a constitutive producer of peroxynitrite, dose-dependently inhibited insulin-stimulated glucose uptake. While SIN-1 did not affect the insulin receptor protein level and tyrosine phosphorylation, it reduced the insulin receptor substrate-1 (IRS-1) protein level, and IRS-1 associated phosphatidylinositol-3 kinase (PI-3 kinase) activity. Although SIN-1 did not induce Ser307 phosphorylation of IRS-1, tyrosine nitration of IRS-1 was detected in SIN-1-treated-Rat1 fibroblasts expressing human insulin receptors. Mass spectrometry showed that peroxynitrite induced at least four nitrated tyrosine residues in rat IRS-1, including Tyr939, which is critical for association of IRS-1 with the p85 subunit of PI-3 kinase. Our results suggest that peroxynitrite reduces the IRS-1 protein level and decreases phosphorylation of IRS-1 concurrent with nitration of its tyrosine residues. 相似文献
72.
Haff GG Carlock JM Hartman MJ Kilgore JL Kawamori N Jackson JR Morris RT Sands WA Stone MH 《Journal of strength and conditioning research / National Strength & Conditioning Association》2005,19(4):741-748
Six elite women weightlifters were tested to evaluate force-time curve characteristics and intercorrelations of isometric and dynamic muscle actions. Subjects performed isometric and dynamic mid-thigh clean pulls at 30% of maximal isometric peak force and 100 kg from a standardized position on a 61.0 x 121.9 cm AMTI forceplate. Isometric peak force showed strong correlations to the athletes' competitive snatch, clean and jerk, and combined total (r = 0.93, 0.64, and 0.80 respectively). Isometric rate of force development showed moderate to strong relationships to the athletes' competitive snatch, clean and jerk, and combined total (r = 0.79, 0.69, and 0.80 respectively). The results of this study suggest that the ability to perform maximal snatch and clean and jerks shows some structural and functional foundation with the ability to generate high forces rapidly in elite women weightlifters. 相似文献
73.
Kaneto H Nakatani Y Kawamori D Miyatsuka T Matsuoka TA Matsuhisa M Yamasaki Y 《The international journal of biochemistry & cell biology》2005,37(8):1595-1608
Type 2 diabetes is the most prevalent and serious metabolic disease affecting people all over the world. Pancreatic beta-cell dysfunction and insulin resistance are the hallmark of type 2 diabetes. Normal beta-cells can compensate for insulin resistance by increasing insulin secretion and/or beta-cell mass, but insufficient compensation leads to the onset of glucose intolerance. Once hyperglycemia becomes apparent, beta-cell function gradually deteriorates and insulin resistance aggravates. Under diabetic conditions, oxidative stress and endoplasmic reticulum stress are induced in various tissues, leading to activation of the c-Jun N-terminal kinase pathway. The activation of c-Jun N-terminal kinase suppresses insulin biosynthesis and interferes with insulin action. Indeed, suppression of c-Jun N-terminal kinase in diabetic mice improves insulin resistance and ameliorates glucose tolerance. Thus, the c-Jun N-terminal kinase pathway plays a central role in pathogenesis of type 2 diabetes and could be a potential target for diabetes therapy. 相似文献
74.
The decay kinetics of tyrosine Z (Yz) in Tris-treated PhotosystemII particles were measured by time-resolved EPR at differentpH values (pH 5.5 to 7.5) between 230 and 297 K. Yz inducedby laser flashes decayed in a biphasic wav; t values were about100 ms in the fast phase and about 1 s in the slow one, respectively,at room temperature. The fast phase was attributed to a recombinationof charges on Yz and QA. The activation energies forthe reaction of Yz with QA between 245 and 297 K havebeen estimated to be more than 38 kJ mol1 at pH (>6.5)and less than 32 kJ mol1 at pH (<6.0), respectively.The activation energy gap between high pH (>6.5) and lowpH (<6.0) ranges was found to be E=4.4 kJ mol1. Judgingfrom the fact that pH 6.2 appears to be the border between thehigh and low pH regions, we suggest that the kinetics of Yzis strongly influenced by the dissociation of the nearby histidineresidue. (Received February 21, 1997; Accepted June 24, 1997) 相似文献
75.
Kamiyama M Kobayashi M Araki S Iida A Tsunoda T Kawai K Imanishi M Nomura M Babazono T Iwamoto Y Kashiwagi A Kaku K Kawamori R Ng DP Hansen T Gaede P Pedersen O Nakamura Y Maeda S 《Human genetics》2007,122(3-4):397-407
Using a large-scale genotyping analysis of gene-based single nucleotide polymorphisms (SNPs) in Japanese type 2 diabetic patients,
we have identified a gene encoding neurocalcin δ (NCALD) as a candidate for a susceptibility gene to diabetic nephropathy; the landmark SNP was found in the 3′ UTR of NCALD (rs1131863: exon 4 +1340 A vs. G, P = 0.00004, odds ratio = 1.59, 95% CI 1.27–1.98). We also discovered two other SNPs in exon 4 of this gene (+999 T/A, +1307
A/G) that showed absolute linkage disequilibrium to the landmark SNP. Subsequent in vitro functional analysis revealed that
synthetic mRNA corresponding to the disease susceptible haplotype (exon 4 +1340 G, +1307 G, +999 A) was degraded faster than
mRNA corresponding to the major haplotype (exon 4 +1340 A, +1307 A, +999 T), and allelic mRNA expression of the disease susceptibility
allele was significantly lower than that of the major allele in normal kidney tissues. In an experiment using a short interfering
RNA targeting NCALD, we found that silencing of the NCALD led to a considerable enhancement of cell migration, accompanied by a significant reduction in E-cadherin expression, and
by an elevation of α smooth muscle actin expression in cultured renal proximal tubular epithelial cells. We also identified
the association of the landmark SNP with the progression of diabetic nephropathy in a 8-year prospective study (A vs. G, P = 0.03, odds ratio = 1.91, 95% CI 1.07–3.42). These results suggest that the NCALD gene is a likely candidate for conferring susceptibility to diabetic nephropathy.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
76.
T Ono H Nakayama H Gleiter Y Inoue A Kawamori 《Archives of biochemistry and biophysics》1987,256(2):618-624
Properties of the S2 state formed in photosystem II membranes in which Cl- had been replaced by various anions were investigated by means of thermoluminescence measurements and low temperature EPR spectroscopy. The Br--substituted membranes showed the normal thermoluminescence B-band arising from S2Q-B charge recombination, whereas the SO2-4-, F--, CH3COO--, and NO-3-substituted membranes showed modified B-bands with variously upshifted peak temperatures. The extent of the peak temperature upshift varied in parallel with the extent of inhibition of O2 evolution depending on the anion species. A normal EPR S2 multiline signal was induced in Br--substituted membranes, but its amplitude was reduced to less than 10% in F--, NO-3-, CH3COO--, and SO2-4-substituted membranes, In contrast, the g = 4.1 signal from S2 was markedly enhanced in F-- and NO-3-substituted membranes, not much affected in CH3COO-- and SO2-4-substituted membranes, and decreased to 70% in Br--substituted membranes. Based on these data, the effect of various types of S2 modification on the O2-evolving activity was discussed. It was suggested that anions have an important role in regulating the interaction between the Mn atoms, and thereby adjust the redox properties of the S2 state to enable further transitions beyond S2. 相似文献
77.
Marion Cornu Honey Modi Dan Kawamori Rohit N. Kulkarni Magali Joffraud Bernard Thorens 《The Journal of biological chemistry》2010,285(14):10538-10545
78.
Crum AJ Kawamori N Stone MH Haff GG 《Journal of strength and conditioning research / National Strength & Conditioning Association》2012,26(4):914-925
Limited research exists examining the effect of moderately loaded conditioning activities that are employed as part of a strength-power potentiating complex (SPPC). Additionally, no studies to date have explored the effects of using a concentric-only quarter back squat protocol as part of an SPPC. Therefore, the purpose of this study was to examine the effects of a moderately loaded (50-65% of 1RM) concentric-only quarter back squat protocol on the occurrence of potentiation effects at various time points. Twenty men who could quarter back squat a minimum of 2.4 times their body mass (3.7 ± 0.7 kg·per body mass) participated in this investigation. All subjects participated in 3 conditions: control (CT), a 50% of 1RM trial (50POT), and a 65% of 1RM trial (65POT). One minute before each condition, a maximal countermovement vertical jump (CMJ) was performed. One minute later, the subject performed 1 of 3 conditions: CT condition, 50POT, or 65POT, followed by vertical jumps at 0.5, 3, 5, 10, and 15 minutes after conditioning activity. A force plate was used to quantify displacement, peak power output, peak force, and the rate of force development for each CMJ. There were no significant differences (p > 0.05) in any of the performance measures quantified during the CMJ trials when comparing the CT, 50POT, and 65POT treatment conditions. However, 48% of the subjects demonstrated some degree of potentiation at the 30 seconds after completing the 65POT trial, but this percent increase was not statistically significant. From a practical perspective, if the goal of the SPPC is to create a maximization of the potentiation effect, moderately loaded activities may not be the best alternative. 相似文献
79.
Mikio Kawamori Yasushi Morikawa Seigo Takasawa 《Applied microbiology and biotechnology》1986,24(6):449-453
Summary Cellulase production in Trichoderma reesei mutants was induced by l-sorbose, known to be an inhibitor of -1,3-glucan synthesis. In the experiments the washed mycelia were used as resting cells. For CMCase induction over 24 h using T. reesei PC-3-7, the most effective pH, temperature and l-sorbose concentration were 2.8, 28° C and 0.3 mg/ml, respectively. Comparison with other cellulase inducers showed that the inductive level of CMCase by l-sorbose was similar to that by sophorose, known to be the most potent inducer of cellulases. Since the induction of CMCase was inhibited completely by 10 g of cycloheximide per ml, the induction process was considered to involve de novo synthesis. Although l-sorbose had the effective inducibility of CMCase, the assimilation rate of l-sorbose was very low in T. reesei PC-3-7.Production of Ethanol from Biomasses. Part III.Production of Ethanol from Biomasses. Part III. 相似文献
80.
The light-induced new EPR signals at g = 12 and 8 were observed in photosystem II (PS II) membranes by parallel polarization EPR. The signals were generated after two flashes of illumination at room temperature, and the signal intensity had four flashes period oscillation, indicating that the signal origin could be ascribed to the S3-state. Successful simulations were obtained assuming S = 1 spin for the values of the zero-field parameters, D = +/-0.435 +/- 0. 005 cm-1 and E/D = -0.317 +/- 0.002. Orientation dependence of the g =12 and 8 signal intensities shows that the axial direction of the zero-field interaction of the manganese cluster is nearly parallel to the membrane normal. 相似文献