Gas chromatography-mass spectrometric analysis of 3-methyl-cholanthrene metabolism in vivo

Metabolites of 3-methylcholanthrene in tissues and excreta of rats and mice were extracted, directly or after removal from conjugation, with ethanol or ethyl acetate, purified by Sephadex LH-20 column chromatography, and examined by gas chromatography-mass spectrometric analysis. Data from the present experiments showed that the extracts after chromatographic purification were contaminated with some tissue-derived sterols such as cholesterol. As compounds related to 3-methylcholanthrene, a dehydro compound, 1- and 2-hydroxy compounds, 11-phenol and two other phenols were identified in the extracts. Some Ketones and cis-1,2-dihydroxy compounds were also detected on occasion. Some trihydroxy compounds were suggested. This is of interest because the trihydroxylated metabolites have been pointed out as precursors of ultimate carcinogen of MC recently. The high sensitivity of the lung to MC carcinogenesis was not interpreted only by specific distribution in tissue of metabolites of the hydrocarbon.