1993 Fiscal Year Final Research Report Summary
Pharnacological and physiological sihnificance of cytochrome P450 isozymes in mammalian brain tissues
| Project/Area Number |
04671341
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
Biological pharmacy
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| Research Institution | Chiba University |
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Principal Investigator |
NARIMATSU Shizuo Chiba Univ. Dept. Biopharm. Assoc. Prof., 薬学部, 助教授 (20113037)
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| Co-Investigator(Kenkyū-buntansha) |
MASUBUCHI Yasuhiro Chiba Univ. Dept. Biopharm. Res. Assoc., 薬学部, 助手 (10209455)
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| Project Period (FY) |
1992 – 1993
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| Keywords | brain microsones / cytochrome P450 / bunitrolol / propranolol / CYP2D subfamily / P450BTL / CYP1A subfamily / P450sudan I-1 |
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| Research Abstract |
We proceeded with project to clarify the phisological roles of cytochrome P450(CYP)isozymes in the brain tissues. The results obtained were as follows : 1) Activities for bunitrolol (BTL) 4-hydroxylation and propranolol (PL) oxidation were detected in microsomal fractions form whoke brain or dissected brain tissues of rats, rabbits, pigs and cows. The activities ranged from 1 to0.1% of those in liver mictosomes of the animal species. 2) BTL 4-hydroxylase activity in rabbit brain microsomes were partially inhibited by antibodies raised against rat liver P450sudan I-1 (CYP1A1) and P450BTL (CYP2D2). Considering that BTL 4-hydroxylase activity in rabbit liver microsomes was not inhibited by the antibodies, theCYP isozymes were thought to be differnt between rabbit liver and brain tissues. 3) CYP isozymes were probed with the antibodies against rat liver microsomes in the western blot analysis of rabbit and pig brains. The analysis whowed that CYP isozymes cross-reacted with rat liver P450sudan I-1 and P450BTL existed both in rabbit and pig brain tissues. 4) P450BTL aonsisted of a larger (50kD)and a smaller molecular mass (32KD) proteins. The combination was needed for the highest activiy for BTL 4-hydroxylation. The two proteins were separated by SDS-PAGE,and only antibodies ageinst the 54KD protein were obtained. the Western blot analysis of pig brain tissues with the antibodies showed results similar to those with the antibodies ageinst the mixture of 50 and 32KD proteins. These results indicate that CYP2D isozymes as well as other subfamikies exist and have vertain activities in brain tissues microsomes from various mammals.
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