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ID 20982
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Inhibitory Effect of Paraquat on Biotransformation of Halothane in Rabbit Liver Microsomes
creator
subject
Paraquat
Anesthetic
Halothane
Biotransformation
NDC
Medical sciences
abstract
Microsomal fractions were prepared from the liver of rabbits to investigate the effects of paraquat (methyl viologen) on generation of metabolites of halothane under the optimal aerobic and anaerobic conditions. Halothane (CF3CHClBr) is known to undergo oxidative and reductive biotransformation in the hepatic mixed function oxidase system including cytochrome-P450 reductase and cytochrome P450. The results showed that paraquat inhibited generation of metabolites of halothane under these conditions. Generation of the aerobic metabolite, trifluoroacetic acid (CF3COOH), and anaerobic metabolites・ 2-chloro-1,1,1-trifluoroethane (CF3CH2Cl) and 2-chloro-1,1-difluoroethylene (CF2CHCl), were inhibited 50% by 4.96 mM and 35.3 mM paraquat, respectively. Possible mechanisms were speculated on to account for the inhibitory effects: one being the impaired formation of halothanecytochrome P450 complex by addition of paraquat, and the other the diversion of electrons from cytochrome-P450 reductase to generate active paraquat radicals. It is concluded that paraquat inhibits NADPH-dependent biotransformation of halothane catalyzed in mixed function oxidase system.
description
Hiroshima J Med Sci. 1989 Dec;38(4):161-7.
language
eng
nii type
Thesis or Dissertation
HU type
Doctoral Theses
DCMI type
text
format
application/pdf
rights
Copyright(c) by Author
grantid
乙第1915号
degreeGrantor
広島大学(Hiroshima University)
degreename Ja
博士(医学)
degreename En
Medicine
degreelevel
doctoral
date of granted
1984-11-20
department
Graduate School of Biomedical Science