ID | 17050 |
Eprint ID | 17050
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FullText URL | |
Title Alternative | Steroid hormone metabolism in the brain: Part 2. Occurence of 3α-hydroxysteroid dehydrogenase and the effect of central acting drugs on the enzyme activity.
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Author |
Kaneyuki, Takao
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Abstract | In previous study, I have reported that ⊿(4)-3-ketosteroid 5α-oxidoreductase activity in the rat diencephalon was decreased by diphenylhydantoin, imipramine and chlorpromazine administered intraperitoneally. At the same time, it was observed that 5α-androstan-3α, 17β-diol formation was decreased. In this paper, I report on the occurrence of 3α-hydroxy-steroid dehydrogenase and the effect of the central acting drugs on the enzyme activity. The results were as follows. 1) 0.2 μ Ci of 4.(14)C-dihydrotestosterone (specific activity 50.6mCi/mM), 1 ml of rat diencephalon homogenate (about 8 mg protein) and NADPH (95μM/L) were mixed together and the total volume was adjusted to 2.5ml with phosphate buffer (pH 7.0). The reaction mixture was incubated at 38℃ for 120min. with continual shaking, the reaction contents were exposed to air. A sample of enzyme preparation placed in a boiling water bath for 5min. was used as blank. Identification of the metabolite was performed by TLC and GLC. 5α-androstan-3α, 17β-diol was confirmed as principal metabolite. 2) The occurrance of 3α-hydroxysteroid dehydrogenase was confirmed in rat diencephalon. Optimal pH of the enzyme was around 7.0 and apparent Km values was estimated as 5.9 x 10(-6)M. 3) Male Wistar rats weighing about 100g were divided into four groups. Each group received chlorpromazine HCl (0.4mg/0.1ml/100g body weight), imipramine HCl (0.1mg/0.1ml/100g body weight), sodium diphenylhydantoin (0.5mg/0.1ml/100g body weight) or normal saline (0.1ml/100g body weight) intraperitoneally for 14 consecutive days respectively. 24 hours following the last administration of the drug, the rats were killed by decapitation. Diencephalon was removed and homogenated with 9 volumes of phosphate buffer (pH 7.0). Homogenated were incubation with dihydrotestosterone and NADPH for the estimation of the 3α-hydroxysteroid dehydrogenase activity. The enzyme activity was not affected by these drugs.
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Published Date | 1977-02-28
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Publication Title |
岡山医学会雑誌
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Publication Title Alternative | Journal of Okayama Medical Association
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Volume | volume89
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Issue | issue1-2
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Publisher | 岡山医学会
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Publisher Alternative | Okayama Medical Association
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Start Page | 13
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End Page | 19
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ISSN | 0030-1558
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NCID | AN00032489
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Content Type |
Journal Article
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Official Url | https://www.jstage.jst.go.jp/article/joma1947/89/1-2/89_1-2_13/_article/-char/ja/
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Related Url | http://www.okayama-u.ac.jp/user/oma/index.html
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language |
Japanese
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Copyright Holders | 岡山医学会
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File Version | publisher
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Refereed |
True
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Eprints Journal Name | joma
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