The effect of adaptation on the metabolism of dodecylthioacetic acid (a 3-thia fatty acid) in rat tissues.

Dodecylthioacetic acid (DTA) was both omega-hydroxylated and sulfur-oxygenated at about equal rates by the microsomal fraction from liver and kidney. Feeding tetradecylthioacetic acid (TTA) for 4 days increased omega-hydroxylation 4-fold only in the liver. The sulfur oxygenation rate was similar in liver, kidney and lung, barely detectable in heart and absent in intestinal mucosa. In isolated hepatocytes from normal rats the major metabolite from dodecylthioacetic acid was carboxypropylsulfoxyacetic acid. In hepatocytes from adapted rats, the main product was identified as bis(carboxymethyl)sulfide. In kidney perfusion experiments dodecylthioacetic acid was metabolized to carboxypropyl-sulfoxyacetic acid and preferentially excreted in the urine. In hindquarter perfusion experiments no oxidative metabolites were detected. These experiments show that only liver and kidney can metabolize dodecylthioacetic acid completely and that omega-hydroxylation in the liver is the only inducible activity, in addition to the beta-oxidation.