Metabolism of Halogenated Compounds—Biodehalogenation

  • Kenneth L. Kirk
Part of the Biochemistry of the Elements book series (BOTE, volume 9A+B)


The metabolism of halogenated hydrocarbons in vivo is initiated predominantly by two classes of enzymes—the cytochrome P-450-dependent monooxygenases and the glutathione S-transferases. These enzymes, in general, convert nonexcretable lipophilic compounds ultimately to hydrophilic metabolites that can be eliminated in urine and/or bile. For example, oxidative replacement of halogen with hydroxyl followed by glucuronide formation is a major pathway for detoxification and excretion. On the other hand, processes initiated by these enzymes are often responsible for conversion of a relatively harmless substrate into a more toxic or carcinogenic intermediate. Bioactivation of xenobiotics to toxic and/or carcinogenic metabolites has been the subject of extensive research and will be discussed in this chapter. The role of deiodinases in thyroid hormone function was discussed in some detail in Chapter 6. This will be reconsidered briefly in this chapter in the context of biodehalogenation mechanisms. Metabolism and detoxification of special classes of halogenated compounds (pesticides, TCDD, etc.) will also be considered.


Carbon Tetrachloride Reductive Dechlorination Mercapturic Acid Diol Epoxide Vinyl Bromide 
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© Plenum Press, New York 1991

Authors and Affiliations

  • Kenneth L. Kirk
    • 1
  1. 1.National Institutes of HealthBethesdaUSA

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