The metabolic fate of cholesterol-5 alpha, 6 alpha-expoxide in vivo

[14C] Cholesterol-5 alpha, 6 alpha-expoxide, administered to mice by either gastric intubation or skin painting, was rapidly and primarily excreted in the feces. Residual amonts of the epoxide and its metabolites were found in a wide variety of organs, and persisted for at least 72 hr. At some sites (principally the liver, the small intestinal contents and the combined stomach/duodenum and their contents), the labeled compound existed in a water-soluble form which could not be extracted with chloroform/methanol. Treatment of the small intestinal contents with a preparation of beta-glucuronidase/sulfatase produced a marked increase in the amount of organic-solvent-extractable cholesterol-alpha-epoxide and other polar metabolites. Unchanged epoxide was found mainly in the feces and the skin at the site of application. On the basis of these results, stool specimens, and not blood samples, should be analyzed to detect the presence of this compound and/or its metabolites in vivo.