Oxybiotin metabolism in the chick; deposition of oxybiotin in tissues.

Oxybiotin, the oxygen analogue of biotin, can replace biotin in the nutrition of the rat (l), the chick (2), and certain microorganisms (3). It has been clearly established that Saccharomyces cerevisiae and Rhizobium trifolii can utilize oxybiotin directly (4, 5). Recently Krueger and Peterson (6) have obtained similar results with Lactobacillus pentosus. The present experiments were designed to determine whether oxybiotin is active as such or whether it is converted into biotin by the chick. If oxybiotin is active as such, its administration to biotin-deficient animals should lead to an accumulation of oxybiotin in the tissues with no concomitant increase in their biotin content. Furthermore, there should be a correlation between the growth response of the animals and the oxybiotin content of tissues. This paper presents the results of a study of the deposition of oxybiotin and biotin in chick tissues following the intramuscular administration of these compounds. By differential assay for biotin and oxybiotin it has been possible to demonstrate that the increased “biological activity” (or biotin-like activity) of tissues (as measured microbiologically) which appears after the administration of oxybiotin to chicks is due to oxybiotin rather than biotin. The growth response of chicks was found to parallel the increase in the oxybiotin content of their tissues.