Michiko Fukuhara

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Effects of co-administration of food additives and naturally occurring food components were studied on the activation of mutagens. Male mice (ddY) were given diets containing butylated hydroxytoluene (BHT) or butylated hydroxyanisole (BHA) and flavone or flavanone (2,3-dihydroflavone) for two weeks and the ability of hepatic microsomes to activate aflatoxin(More)
An aqueous extract of a poisonous mushroom, Amanita abrupta was injected intraperitoneally into male ICR mice and the acute effects on the liver were studied. Contents of serum glucose and liver glycogen decreased to 60% and 10% of the control levels, respectively, 6 h after injection. Activities of serum glutamic oxaloacetic transaminase and serum glutamic(More)
Recently, we isolated a novel Syrian hamster cDNA clone that encodes a protein which has been named CYP3A31. In primary hepatocyte cultures, CYP3A31 is dramatically induced by phenobarbital. To elucidate the mechanism of this induction, we first studied the effects of cAMP on phenobarbital-induced CYP3A31 expression using forskolin and N6,O2'-dibutyryl cAMP(More)
CYP2A8 is a major form of cytochrome P-450 inducible by 3-methylcholanthrene in Syrian hamster liver. To identify DNA elements necessary for the transcriptional activation of the CYP2A8 gene, we analyzed the regulatory region of the CYP2A8 gene and conducted transient transfection experiments of CYP2A8-luciferase fusion plasmids in primary cultures of(More)
Cytochrome P-450AFB is major isozyme inducible by 3-methylcholanthrene in Syrian golden hamsters and shows high potency toward aflatoxin B1 activation. We have isolated and sequenced cDNA clones to P-450AFB by immunoscreening a hamster liver cDNA library in lambda gt11. The longest clone contains an open reading frame of 1482 nucleotides and encodes a(More)
In Syrian hamster liver, treatment with 3-methylcholanthrene (3-MC) markedly induces an isozyme of cytochrome P450 (CYP), CYP2A8. To elucidate the mechanism of this induction, we studied the effect of okadaic acid (OA), an inhibitor of serine threonine protein phosphatases 1 and 2A, on 3-MC-induced CYP2A8 expression in primary cultures of Syrian hamster(More)
Monooxygenases of Chinese hamster livers were characterized with respect to aflatoxin B1 activation and cytochrome P450 isozymes. Polychlorinated biphenyl (PCB)-treatment induced higher activity for aflatoxin B1 activation in Chinese hamsters than in rats and this activity was more elevated by the treatment with phenobarbital than with 3-methylcholanthrene,(More)
An isozyme of cytochrome P-450 catalyzing lanosterol 14 alpha-demethylation was purified from human liver using column chromatography, including immunoaffinity chromatography. The purified protein exhibited a single protein band (53 kDa) on sodium dodecylsulfate-polyacrylamide gel electrophoresis. When reconstituted with NADPH-cytochrome P-450 reductase,(More)