研究者業績

今井 洋一郎

imai yoichiro

基本情報

所属
藤田保健衛生大学 医療科学部 臨床工学科 専門基礎医学 教授
学位
博士(医学)

J-GLOBAL ID
200901026834229797
researchmap会員ID
1000132553

MISC

 14
  • Yoshiji Ohta, Koji Yashiro, Shingo Kaida, Yoichiro Imai, Koji Ohashi, Akira Kitagawa
    CELL BIOCHEMISTRY AND FUNCTION 31(3) 254-262 2013年4月  
    We examined whether water-immersion restraint stress (WIRS) disrupts nonenzymatic antioxidant defense systems through ascorbic acid depletion in the adrenal gland of rats. Rats were exposed to WIRS for 0.5, 1.5, 3 or 6h. WIRS increased serum adrenocorticotropic hormone, corticosterone and glucose concentrations and adrenal corticosterone content at each time point. WIRS increased adrenal lipid peroxide content at 3 and 6h, and the increase was twofold higher than the unstressed level at 6h. WIRS decreased adrenal ascorbic acid content at each time point, and the decrease reached one-third of the unstressed level at 6h. WIRS increased adrenal reduced glutathione content at 0.5 and 6h but reduced that content to half of the unstressed level at 6h. WIRS increased adrenal -tocopherol content at 1.5h but returned that content to the unstressed level thereafter. When rats with 6h of WIRS was orally preadministered with l-ascorbic acid (250mg/kg), WIRS-induced changes in adrenal lipid peroxide, ascorbic acid and reduced glutathione contents were attenuated without any change in stress response. These results indicate that WIRS disrupts nonenzymatic antioxidant defense systems through rapid and continuous ascorbic acid depletion in the adrenal gland of rats. Copyright (c) 2012 John Wiley & Sons, Ltd.
  • Yoshiji Ohta, Koji Yashiro, Koji Ohashi, Yoichiro Imai, Chiaki Kusumoto, Tatsuya Matsura, Mayumi Hidaka, Kenji Fukuzawa
    JOURNAL OF NUTRITIONAL SCIENCE AND VITAMINOLOGY 59(2) 79-86 2013年4月  
    We examined the effect of vitamin E depletion on liver oxidative damage in rats with water-immersion restraint stress (WIRS). Male Wistar rats were fed a normal diet (N) or vitamin E-depleted diet (VE-D) for 4 wk. N- and VE-D-fed rats were exposed to WIRS for 6 h. The activities of serum transaminases and lactate dehydrogenase and serum ascorbic acid concentration were similar in both diet groups. WIRS exposure increased these serum enzyme activities and the serum ascorbic acid concentration in both diet groups but the ratios of these increases were higher in VE-D-fed rats than in N-fed rats. Serum and liver a-tocopherol concentrations in VE-D-rats were approximately 50% and 30% of those in N-fed rats, respectively. WIRS exposure reduced liver alpha-tocopherol concentration in VE-D-fed rats, but not in N-fed rats. Liver ascorbic acid and reduced glutathione concentrations were higher in the VE-D-fed group than in the N-fed group. WIRS exposure reduced liver ascorbic acid and reduced glutathione concentrations in both diet groups. There were no differences in liver concentrations of coenzyme Q(9) or coenzyme Q(10) in the reduced form between the N- and VE-D-fed groups. WIRS exposure reduced liver concentrations of coenzyme Q(9) and coenzyme Q(10) in the reduced form in both diet groups. Liver lipid peroxide concentration was higher in the VE-D-fed group than in the N-fed group. WIRS exposure raised liver lipid peroxide concentration more in the VE-D-fed group than in the N-fed group. These results indicate that vitamin E depletion enhances liver oxidative damage in rats with WIRS.
  • 八代耕児, 今井洋一郎, 太田好次
    潰瘍 40 30-33 2013年  
  • Yoshiji Ohta, Koji Yashiro, Koji Ohashi, Yoichiro Imai
    JOURNAL OF CLINICAL BIOCHEMISTRY AND NUTRITION 51(2) 136-142 2012年9月  
    We examined whether non-enzymatic antioxidant defense systems are disrupted in the brain of rats with water-immersion restraint stress. When rats were exposed to water-immersion restraint stress for 1.5, 3 or 6 h, the brain had decreased ascorbic acid and reduced glutathione contents and increased lipid peroxide and nitric oxide metabolites contents at 3 h and showed further changes in these components with a reduction of vitamin E content at 6 h. Increased serum levels of stress markers were found at 1.5, 3 or 6 h of WIRS. Oral pre-administration of L-ascorbic acid (1.5 mmol/kg) or vitamin E (0.5 mmol/kg) to rats with 6 h of water-immersion restraint stress attenuated the increases in lipid peroxide and nitric oxide metabolites contents and the decrease in vitamin E content in the brain. Pre-administered L-ascorbic acid attenuated the decreases in brain ascorbic acid and reduced glutathione contents at 6 h of water-immersion restraint stress, while pre-administered vitamin E enhanced the decreases in those contents. Pre-administered L-ascorbic acid or vitamin E did not affect the increased serum levels of stress markers in rats with 6 h of water-immersion restraint stress. These results indicate that water-immersion restraint stress causes disruption of nonenzymatic antioxidant defense systems through enhanced lipid peroxidation and nitric oxide generation in the brain of rats with water-immersion restraint stress.
  • Yoshiji Ohta, Koji Yashiro, Mayumi Hidaka, Minako Honda, Yoichoro Imai, Koji Ohashi, Kenji Fukuzawa
    REDOX REPORT 17(5) 200-205 2012年9月  
    Objectives: We examined whether a single exposure of rats to water-immersion restraint stress (WIRS) induces oxidative stress in the thymus and spleen. Methods: Vitamin E, ascorbic acid, reduced glutathione (GSH), and lipid peroxide (LPO) were assayed in the thymus and spleen of rats with and without 6 hours of WIRS. Results: In unstressed rats, vitamin E, ascorbic acid, GSH, and LPO levels were higher in the thymus than in the spleen. Thymic ascorbic acid level was lower in stressed rats than in unstressed rats. Splenic ascorbic acid level was similar in both groups. Thymic and splenic GSH levels were lower in stressed rats than in unstressed rats but the reduced amount of GSH was lower in the spleen than in the thymus. Thymic vitamin E level was lower in stressed than in unstressed rats. Splenic vitamin E level was higher in stressed rats than in unstressed rats. Thymic and splenic LPO levels were higher in stressed rats than in unstressed rats but the increased amount of LPO was higher in the thymus than in the spleen. Conclusion: It is indicated that a single expose of rats to WIRS induces oxidative stress more severely in the thymus than in the spleen.

書籍等出版物

 1

講演・口頭発表等

 31

教育内容・方法の工夫(授業評価等を含む)

 1
  • 件名
    担当科目(生化学、臨床生化学、生化学・臨床生化学・同実習)の授業アンケートに対する改善努力
    開始年月日
    2009/04/01
    概要
    講義は教科書記載内容に準じ板書を基本としている。学生からの講義アンケート結果に基づき、補足あるいは参考資料の配布や視覚化が望ましい内容をPowerPointで提示し、その詳説に理解を促す努力を行っている。しかし、その利用頻度はまだ少なく、視覚データの蓄積と同時に、丁寧に板書することと、講義の声を明瞭にするよう努力を行っている。

作成した教科書、教材、参考書

 3
  • 件名
    生化学・臨床生化学実習用冊子(学内)
    開始年月日
    2009/04/01
    概要
    実習用冊子:医療科学部(臨工)3年対象の同実習冊子を作成した。
  • 件名
    臨床工学技士国家試験対策用入門書・追補(学内)
    開始年月日
    2009/04/01
    概要
    入門書・追補:国試出題基準に基づく解答のうち「生化・臨化」を担当した。
  • 件名
    新版 臨床化学 第3版 講談社サイエンティフィク(分担執筆中)
    開始年月日
    2009/04/01
    概要
    新版教科書:講談社からの依頼により「非蛋白性窒素」の一部を執筆中。2014年秋に刊行予定。

その他教育活動上特記すべき事項

 2
  • 件名
    学生指導副委員長(2009年4月〜2012年3月、医療科学部:臨工) 
    開始年月日
    2009/04/01
    終了年月日
    2013/03/31
    概要
    学生指導副委員長として、学生の日常生活におけるケア(健康問題、事故対策、各種行事遂行支援)に当たった。
  • 件名
    就職対策副委員長(2012年4月〜2014年3月、医療科学部:臨工)
    開始年月日
    2009/04/01
    終了年月日
    2013/03/31
    概要
    2012年4月より(臨工内)就職対策を担当し、キャリア支援課と連携を諮りながら進めた。就職率は、学生の自己開拓も含め、内定率98〜100%の結果を得た。