| Project/Area Number |
63490001
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
広領域
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| Research Institution | Hokkaido University |
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Principal Investigator |
KAMATAKI Tetsuya Fac, of Pharmaceu. Sci., Hokkaido Univ., Professor, 薬学部, 教授 (00009177)
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| Co-Investigator(Kenkyū-buntansha) |
OHI Hiroaki Fac. of Pharmaceu. Sci., Hokkaido Univ., Assistant, 薬学部, 助手 (60194065)
KOMORI Masayuki Fac. of Pharmaceu. Sci., Hokkaido Univ., Assistant, 薬学部, 助手 (40183347)
KITADA Mitsukazu Fac. of Pharmaceu. Sci., Hokkaido Univ., Associate Professor, 薬学部, 助教授 (90110345)
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| Project Period (FY) |
1988 – 1989
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| Project Status |
Completed (Fiscal Year 1990)
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| Budget Amount *help |
¥5,300,000 (Direct Cost: ¥5,300,000)
Fiscal Year 1989: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 1988: ¥4,300,000 (Direct Cost: ¥4,300,000)
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| Keywords | Cytochrome P-450 / Hamster / Liver microsomes / Drug Metabolizing enzyme / Sex difference / Purification / チトクロ-ムP-450 / ハムスター / 肝ミクロゾーム / チトクロームP-450 |
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| Research Abstract |
Three forms of cytochrome P-450 were purified to electrophoretical homogeneity on SDS-PAGE. One of the forms of cytochrome P-450 (P-450-fHS1) purified from liver microsomes of female hamster was considered to be mainly present in a low spin state as judged by absolute spectrum of the oxidized form and was cross-reactive with anti-P450-male antibodies. Other forms of cytochrome P-450 Purified from liver microsomes of male and female hamsters according to the cross-reactivity with anti-P-450-male antibodies were tentatively termed P-450-mHS2 and P-450-fHS2, respectively. Chromatographic behavior of P-450-mHS2 on DEAE-5PW column and hydroxylapatite column were identical to those of P-450-fHS2. Judging from the absolute spectra, both cytochromes P-450 were shown to be mainly in low spin states. N-Terminal amino acid sequence of P-450-mHS2 was identical with that of P-450-fHS2 when the first 20 amino acid sequence was compared. In addition, N-terminal amino acid sequence of P-450-fHS2 was f
… More
ound to be 80% homologous to those of P-450-mHS2 and P-450-fHS2. Western blot analysis of liver microsomes of male hamsters with anti-P-450-fHS1 antibodies showed that P-450-fHS1 or cytochrome P-450 immunochemically related to P-450-fHS1 was also present in liver microsomes of male hamsters. However, the amounts of P-450-fHS1 was found to be much higher in female than male. On the contrary, the content of cytochrome P-450 cross-reactive with anti-P-450-mHS2 antibodies in female hamster microsomes was comparable to that in male hamster microsomes. The content of P-450-fHS1 in liver microsomes of female hamsters was decreased by gonadectomy of female hamsters or the administration of testosterone. Treatment of gonadectomized female hamsters with testosterone, but not with estradiol, resulted in further decrease in the amount of P-450-fHS1. On the other hand, the content of P-450-fHS1 or cytochrome P-450 immunochemically related to P-450-fHS1 in male hamster microsomes was virtually unaffected by gonadectomy or the treatment with estradiol whereas the content of the cytochrome P-450 was increased by the treatment of gonadectomized male hamsters with estradiol. Both P-450-fHS2 and P-450-fHS2 were active for 6beta-hydroxylation of progesterone but not for testosterone hydroxylation. P-450-fHS2 catalyzed N-demethylations of aminopyrine, benzphetamine and erythromycin, and O-deethylation of 7-ethoxycoumarin in a recontituted system. P-450-mHS2 catalyzed N-demethylation of erythromycin and O-deethylation 7-ethoxycoumarin but not N-demethylations of aminopyrine and benzphetamine. Less
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