Glutaric acid: A product of tryptophan metabolism

Previous work in this laboratory (Gholson and Henderson 1958) has shown that a major portion of a test dose of DL-tryptophan-7a-C14 is metabolized by the rat to C14O2 via acetate-1-C14, 3-hydroxyanthranilic acid-2-C14 (3-OHAA) being a probable intermediate (Gholson and Henderson 1959). Consideration of possible metabolic sequences between 3-OHAA-2-C14 and acetate-1-C14 suggested some five-carbon dicarboxylic acids as plausible intermediates. A number of these compounds have been tested by the “metabolite overloading” technique (Rothstein and Miller 1954a) in the rat with tryptophan-7a-C14 and 3-OHAA-H3. Isotopes from both of these compounds were incorporated into excreted glutaric acid, but not into any other compound so far tested by this technique.