Absorption and metabolism of 1-14C-methyl linoleate hydroperoxide

The absorption and metabolism of 1-¹⁴C-methyl linoleate hydroperoxide by rats was investigated. After intubation with 2 mg of peroxide, peak¹⁴CO₂ production occurred at 90 min and 25% of the dose was expired in 24 hr. Fortyfive per cent stil remained in the gastrointestinal tract after 24 hr, most of it bound to the stomach epithelium in the form of intact peroxide. Lymph was collected from the thoracic duct 2 hr after intubation and examined for labeled metabolites. Seven per cent of the radioactivity in the lymph was present in a free 1-¹⁴C-hydroxy fatty acid and 31% in its methyl ester. Fifty-seven per cent occurred in lymph triglycerides where it was equally distributed between a 1-¹⁴C-trienoic fatty acid and an unidentified 1-¹⁴C-oxy acid. The radioactivity in liver lipids was associated mainly with randomly labeled normal fatty acids. No¹⁴C-hydroxy acids were detected in liver lipids and no evidence was obtained for the absorption of unchanged peroxide. The hydroxy and trienoic acids appear to be formed during absorption by a reduction-dehydration reaction sequence.