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11.
Ingestion of plasmalogen markedly increased plasmalogen levels of blood plasma in rats 总被引:1,自引:0,他引:1
Plasmalogens, a subclass of phospholipids, are widely distributed in human and animals, and are taken into the body as food.
However, no data exist on the intestinal absorption or fate of ingested plasmalogen. Here, we determined whether dietary plasmalogen
is absorbed and whether blood and tissue concentrations increased in normal male Wistar rats by using four separate experiments.
Phospholipids containing more than 20 wt% of plasmalogen extracted from the bovine brain were incorporated into test diets
(10–15 wt%). In experiment 1, we estimated the absorption rate by measuring the plasmalogen vinyl ether bonds remaining in
the alimentary tract of rats after the ingestion of 2 g of test diet containing 91 μmol plasmalogen. The absorption rate of
plasmalogen was nearly 80 mol% after 4 h, comparable to the total phospholipid content in the test diet. In experiment 2,
we observed no degradation of the plasmalogen vinyl ether bonds under in vitro conditions simulating those of the stomach and small intestinal lumen. In experiment 3 we confirmed a comparable absorption
(36 mol%) by using a closed loop of the upper small intestine in anesthetized rats 90 min after injecting a 10 wt% brain phospholipid
emulsion. Feeding a test diet containing 10 wt% brain phospholipids for 7 d increased plasmalogen concentration threefold
in blood plasma and by 25% in the liver; however, no increases were seen in blood cells, skeletal muscle, brain, lungs, kidneys,
or adipose tissue (experiment 4). We concluded that dietary plasmalogen is absorbed from the intestine and contributes to
a large increase in plasmalogen levels in blood plasma. 相似文献
12.
13.
Tomokazu Saiki Nobuhisa Nakamura Megumi Miyabe Mizuho Ito Tomomi Minato Kazunori Sango Tatsuaki Matsubara Keiko Naruse 《International journal of molecular sciences》2021,22(11)
Schwann cells play an important role in peripheral nerve function, and their dysfunction has been implicated in the pathogenesis of diabetic neuropathy and other demyelinating diseases. The physiological functions of insulin in Schwann cells remain unclear and therefore define the aim of this study. By using immortalized adult Fischer rat Schwann cells (IFRS1), we investigated the mechanism of the stimulating effects of insulin on the cell proliferation and expression of myelin proteins (myelin protein zero (MPZ) and myelin basic protein (MBP). The application of insulin to IFRS1 cells increased the proliferative activity and induced phosphorylation of Akt and ERK, but not P38-MAPK. The proliferative potential of insulin-stimulated IFRS1 was significantly suppressed by the addition of LY294002, a PI3 kinase inhibitor. The insulin-stimulated increase in MPZ expression was significantly suppressed by the addition of PD98059, a MEK inhibitor. Furthermore, insulin-increased MBP expression was significantly suppressed by the addition of LY294002. These findings suggest that both PI3-K/Akt and ERK/MEK pathways are involved in insulin-induced cell growth and upregulation of MPZ and MBP in IFRS1 Schwann cells. 相似文献
14.
Ito J Hirabayashi M Kato M Takeuchi A Ito M Shimada M Hochi S 《Reproduction (Cambridge, England)》2005,129(2):171-180
The present study was undertaken to clarify the relationship between the p34cdc2 kinase activity of in vitro-aged or enucleated rat oocytes and the premature chromosome condensation (PCC) of microinjected cumulus cell nuclei. Wistar rat oocytes were placed in vitro up to 120 min after the animal was killed. The p34cdc2 kinase activity of the oocytes decreased in a time-dependent manner. The incidence of PCC was higher when nuclear injection into intact oocytes was completed in 15-45 min rather than 46-120 min. When rat oocytes were enucleated for subsequent nuclear injection, the p34cdc2 kinase activity transiently increased soon after enucleation but drastically decreased after 30 min. Removal of the cytoplasm instead of the meta-phase-plate did not affect the p34cdc2 kinase activity even after 60 min. PCC occurred in intact and cytoplasm-removed oocytes but not in enucleated oocytes. In contrast, oocytes from BDF1 mice exhibited a p34cdc2 kinase level twice that of rat oocytes and supported PCC despite enucleation. The p34cdc2 kinase level of intact rat oocytes was reduced to the equivalent level of aged (120 min) or enucleated (+60 min) oocytes by a 45 min treatment with roscovitine, an inhibitor of p34cdc2 kinase. None of the roscovitine-treated oocytes supported PCC while half of the control oocytes did. When rat oocytes were treated with MG132, a proteasome inhibitor, delayed inactivation of the p34cdc2 kinase was observed in the MG132-treated oocytes. A significantly higher proportion of the MG132-treated oocytes supported PCC when compared with the control oocytes. Moreover, a higher proportion of MG132-treated and enucleated oocytes carried two pseudo-pronuclei after cumulus cell injection and developed to the two-cell stage when compared with the enucleated oocytes at the telophase-II stage. These results suggest that the decreased level of p34cdc2 kinase activity in aged or enucleated rat oocytes is responsible for their inability to support PCC of microinjected donor cell nuclei and that inhibition of p34cdc2 kinase inactivation by chemicals such as MG132 is in part effective for rat oocytes to promote PCC and further development. 相似文献
15.
Naoki Takahashi Hiroshi Tujii Megumi Katori Kenji Yamashita Daiji Noda Tadashi Hattori 《Microsystem Technologies》2010,16(8-9):1303-1307
We have produced diffraction gratings for obtaining high resolution X-ray phase imaging, such as X-ray Talbot interferometer. These diffraction gratings were required to have a fine, high accuracy, high aspect ratio structure. Therefore, we decided to use the X-rays lithography technique that used synchrotron radiation of the directivity for a manufacture process. The accuracy of the completed structure depends largely on the accuracy of the X-ray mask. In our group, a resin material is conventionally used for the membrane of large X-ray masks. However, X-ray masks comprising a resin membrane have the disadvantage that, after several cycles of X-ray exposure, they crease and sag due to X-ray-derived heat. As a substitute for the conventional resin membrane, we experimentally fabricated a new X-ray mask using a carbon wafer membrane. The newly fabricated X-ray mask was subjected to X-ray exposure experiment. We succeeded in making the structure body which was almost shape. And the experimental results verified that the new mask did not deteriorate even when used repeatedly, demonstrating that it was highly durable. 相似文献
16.
Kotohiko Sekoguchi Koji Mori Masuo Kaji Megumi Miwa Masao Nakazatomi Hideo Shimizu 《亚洲传热研究》1996,25(8):568-579
Gas-liquid interfacial profiles in plug flow for both upward and downward flows were obtained using semi-supermultiple point-electrode probes, comprising 67 sensing tips arranged on a tube diameter. Typical interfacial profiles are demonstrated for both flows. Close inspection of the profiles reveals that four zones exist in a pair of gas and liquid slugs for upward plug flow and a high slip velocity region in downward plug flow. The lengths of the swelling liquid front zone and the wake zone were determined. The length of the wake zone strongly depends on the relative velocity between the liquid film around the gas slug and the liquid phase in the liquid slug. Characteristic distributions of bubbles within liquid slugs were found, i.e., three types of radial distributions of void fraction, namely saddle-shaped, trapezoidal and bullet-shaped distributions, exist for upward flow. The two types for downward flow exclude the saddle-shaped distribution. © 1997 Scripta Technica, Inc. Heat Trans Jpn Res, 25 (8): 568–579, 1996 相似文献
17.
Ohmori T Morita H Tanaka M Miyauchi K Kasai D Furukawa K Miyashita K Ogawa N Masai E Fukuda M 《Journal of Bioscience and Bioengineering》2011,111(4):437-442
Rhodococcus jostii RHA1 accumulates chlorobenzoates (CBA) during the degradation of polychlorinated biphenyls (PCBs). CBA degradation is considered one of the rate-limiting steps in the complete degradation of PCBs. To reduce the accumulation of CBAs, the upper pathway enzyme genes for PCB degradation of RHA1 were introduced into a CBA-degrading bacterium, Burkholderia sp. NK8. The resulting recombinant strain exhibited no biphenyl 2,3-dioxygenase (BphA) activity encoded by bphAaAbAcAd genes, which encode the large and small subunits of the terminal oxygenase component and the ferredoxin and reductase subunits responsible for electron transfer from NADH to the large subunit. The remaining enzyme genes involved in the transformation of biphenyl to benzoate, bphB2C1D1, which encode dehydrogenase, ring-cleavage dioxygenase and hydrolase, conferred activities to NK8. To obtain the BphA activity of RHA1 in NK8, sets of BphA genes were constructed by combining the bphAaAbAcAd genes of RHA1 and bphA3A4 of Pseudomonas pseudoalcaligenes KF707, encoding the ferredoxin and reductase subunits. Hybrid derivatives of BphA containing the KF707 bphA3 conferred BphA activity to NK8, and a derivative containing the RHA1 bphAaAb and KF707 bphA3A4 genes exhibited the highest BphA activity. A plasmid containing the RHA1 bphAaAb and KF707 bphA3A4 genes plus the RHA1 bphB2C1D1 genes was constructed and introduced into NK8. The resulting recombinant strain efficiently degraded 2-, 3- and 4-chlorobiphenyls with an apparent reduction in CBA accumulation in comparison to the recombinant mutant strain, which had an insertion in the cbeA gene to inactivate CBA dioxygenase. 相似文献
18.
19.
Megumi Kawasaki 《Metallurgical and Materials Transactions A》2011,42(10):3035-3045
Processing through the application of severe plastic deformation (SPD) has become an absorbing tool because it provides the
potential for refining the grain size of polycrystalline bulk metals to the submicrometer or even the nanometer level. Several
SPD methods are now available, but the more promising procedures seem to be equal-channel angular pressing (ECAP) and high-pressure
torsion (HPT). This report examines these procedures with an emphasis on the principles of grain refinement and the mechanical
properties developed at high temperatures in materials after processing by ECAP and the hardness homogeneity and microstructural
evolution in materials processed by HPT. Moreover, recent observations on the ECAP and HPT processing also are discussed. 相似文献
20.
Jian-Yu Zheng Shuichi Noguchi Kenjo Miyauchi Masahiro Hamada Kazushi Kinbara Kazuhiko Saigo 《Fullerenes, Nanotubes and Carbon Nanostructures》2001,9(4):467-475
A series of [60]fullerene bis-adducts having a π-electron-rich aromatic ring as a donor in a face-to-face arrangement were synthesized by the bis-cyclopropanation of [60]fullerene with tether-linked bis-malonates. One of the bis-adducts showed a photoinduced intramolecular electron transfer which caused the dramatic quenching of its fluorescence in a polar solvent. 相似文献