The detection of halocarbon-derived radical adducts in bile and liver of rats.

The free radical metabolism of halocarbons has been studied in living animals by the techniques of spin trapping and electron paramagnetic resonance. Earlier work demonstrated that radical adducts of carbon tetrachloride can be detected in the bile of living rats treated with carbon tetrachloride and the spin trap phenyl-N-t-butyl nitrone. In this study, the biles and livers of treated animals have been examined in order to determine the factors that could affect the content of radical adduct detected in bile (e.g. bile flow rate). The approaches used include the quantitation of radiolabeled spin trap and of the trichloromethyl radical adduct in bile and liver, and the pharmacological manipulation of bile flow. Other halogenated hydrocarbons are thought to form free radicals in vivo, and have also been studied by these techniques. Bromotrichloromethane, a brominated analog of carbon tetrachloride, readily forms the same radical adducts as carbon tetrachloride. No radical adduct from chloroform, the corresponding hydrogenated analog, is detectable in bile. Radical adduct is only detectable in bile from bromoform-treated rats after the production of hypoxia.