Metabolism of trichloroethylene in liver microsomes. II. Identification of the reaction product as chloral hydrate.

The product of metabolism of trichloroethylene in rat liver microsomes has been characterized as chloral hydrate. In common with chloral hydrate, the metabolite is converted to dichloroacetic acid upon reaction with basic cyanide; to chloroglyoxal bis-2,4-dinitrophenylhydrazone upon treatment with 2,4-dinitrophenylhydrazine in acid; to trichloroethanol by the action of liver alcohol dehydrogenase; and to trichloroacetic acid upon oxidation mediated by chloral hydrate dehydrogenase. Possible mechanisms of the conversion of trichloroethylene to chloral hydrate are discussed. ACKNOWLEDGMENTS The authors are greatly indebted to Mr. Howard J. Lambert for aid in gas chromatography, and to him and Dr. E. R. Garrett for making available to them their chromatographic method in advance of publication. They also acknowledge the technical assistance of Mr. James D. Hindman in developing colorimetric methods. This work was supported in Part by U. S. Public Health Service Research Grant No. OH-00124.