Effects of biotin deficiency on embryonic development in mice.

OBJECTIVE: The purpose of this investigation was to determine the effects of biotin deficiency on maternal metabolism and embryonic development in pregnant mouse dams. METHODS: The pregnant mice were randomly assigned to one of three dietary groups and given a biotin-deficient diet, biotin-supplemented diet, or biotin-control diet during gestation. On days of gestation (dgs) 0, 4, 8, 12, and 16, organic acids including 3-hydroxyisovaleric acid in urine were discovered by high-performance liquid chromatography, and the biotin level in the serum and urine was determined by a bioassay. On dg 18, fetuses were examined for morphologic development. RESULTS: In the biotin-deficient group, biotin excretion in urine decreased on dg 4 and was subsequently below the lower limit, whereas the urinary concentration of 3-hydroxyisovaleric acid increased after dg 12. In contrast, the biotin concentration in urine significantly increased on dgs 4, 8 and 12 in the biotin-supplemented group, but decreased on dg 16 in the biotin-supplemented and biotin-control groups. The urinary excretion of pyruvic acid in the biotin-deficient group was significantly higher than that in the biotin-supplemented group throughout the entire gestation. These concentrations in urine significantly increased on dg 16 compared with dg 0. The inhibition of embryonic development and external malformations such as cleft palate (100%), micrognathia (100%), and micromelia (91.4%) were also detected in biotin-deficient fetuses. CONCLUSION: These findings indicated that, as the requirement of biotin increases during gestation and/or embryonic development, a large amount of biotin is necessary for maintaining normal reproductive performance during the late stage of gestation.

[Biotin deficiency in amino acid formula nutrition for an infant with milk protein allergy].

We reported a 4-month-old girl with biotin deficiency caused by amino acid formula. Two weeks after birth, she was diagnosed as having a milk protein allergy. After switching to amino acid formula from usual formula, her symptoms and laboratory findings became normal. About three weeks after the beginning of amino acid formula, she developed intractable skin erosions around the eyes, mouth, neck, and anogenital area. By measuring concentrations of some trace elements, she was diagnosed as having a biotin deficit, because of the organic aciduria and undetectable serum biotin concentration. Her serum biotinidase level was normal. Upon administration of oral biotin supplementation, all her symptoms and laboratory findings were dramatically improved. Since amino acid formula contains very few biotin, we should pay attention to biotin deficiency when infants receiving amino acid formula.

Transplacental transport and tissue distribution of biotin in mice at midgestation.

Biotin is a water-soluble vitamin which functions as a coenzyme of carboxylases in glucose and amino acid metabolism and fatty acid synthesis. Biotin is also essential for maintaining reproductive function. Biotin deficiency during gestation induces cleft palate, micrognathia and limb hypoplasia in mouse fetuses at near term. Maternal biotin deficiency is severely tetatogenic in mammals. However, the relationship between abnormal morphogenesis and biotin deficiency is not sufficiently clear. This study was conducted to elucidate the mechanism of biotin transport from dams to embryos and the nutritional roles of biotin in ICR mice. Pregnant mice were given either a biotin-deficient or biotin-supplemented diet, and biotin and biotinidase activity were determined in dams and fetuses. It became evident that biotin was supplied from dams to growing embryos during morphogenesis. In particular, a large amount of biotin was transported to palates and mandibles on days 12-15 of gestation. The transportation of biotin to fetuses differed among fetal growth periods and organs. These results suggest that biotin is an essential nutrient and may play an important role in embryonic growth.