5-Methyltryptophan and Darkening of the Hair in Yellow Ay/a Mice


PREVIOUS experiments have shown that powdered preparations of the skin and hair of yellow (Ay/a) mice oxidize L- (but not D-) tryptophan and also DL-5-hydroxytryptophan with the production of yellow solutions1,2. To obtain further evidence on the question of whether tryptophan, or a derivative, might be implicated in the production of yellow pigment in the hairs of this strain of mice, in vivo experiments were carried out using an antimetabolite of tryptophan3. Starting at 3–4 days of age, daily subcutaneous injections of DL-5-methyltryptophan were made in these mice for a period of 7–10 days. This is a period of vigorous pigment production. (Mice were obtained from the R. B. Jackson Memorial Laboratories, Bar Harbor, Maine. DL-5-methyl-tryptophan was a product of Sigma Chemical Co., St. Louis, Mo.)

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NACHMIAS, V. 5-Methyltryptophan and Darkening of the Hair in Yellow Ay/a Mice. Nature 191, 934–935 (1961). https://doi.org/10.1038/191934b0

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