VITAMINS

Reproductive and Embryotoxic Effects of Biotin Deficiency in Mammals

Toshiaki WATANABE

Article type: Article
1990 Volume 64 Issue 8 Pages 429-440
Published: August 25, 1990
Released on J-STAGE: March 17, 2018

DOIhttps://doi.org/10.20632/vso.64.8_429

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We found that maternal biotin deficiency was severely teratogenic in mammals. Pregnant mice were fed a basal diet that contained the spray-dried egg white as the source of protein throughout gestation. At near term, the biotin-deficient fetuses showed various external and skeletal malformations, such as cleft palate (82.9%), micrognathia (91.2%), micromelia (41.2%), and deformities of cervical vertebral arch (24.1%). Moreover, there were striking species and strain differences in the teratogenicity of biotin deficiency among mice, rats and hamsters. At midgestation, the inhibition of palatal and limb formation by biotin deficiency was observed in mice. The biotin content of the whole embryo was about tenfold greater than liver biotin levels in their dams on day 12 of gestation. Although possible underlying mechanism for this is not clear, at least in these species, biotin is important for normal embryonic growth and development. Biotin is also said to be necessary for the birth of normal viable young and the health of young in domestic fowls and animals. This review discusses the nutritional importance of biotin to the maintenance of reproductive performance and lactation in mammals and humans.

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Biosynthetic Pathway of the Pyrimidine Moiety of Thiamin

Kazuko YAMADA, Hiroshi KUMAKA

Article type: Article
1990 Volume 64 Issue 8 Pages 441-458
Published: August 25, 1990
Released on J-STAGE: March 17, 2018

DOIhttps://doi.org/10.20632/vso.64.8_441

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Biosynthetic pathway of the pyrimidine moiety of thiamin was studied. Procaryotes and eucaryotes have different biosynthetic pathways for the pyrimidine. In procaryotes, the pyrimidine is formed by ring expansion of imidazole accompanied insertion of C-4', C-5' fragment of ribose of 5-aminoimidazole ribonucleotide, a intermediate of purine biosynthesis. In eucaryotes, N-3, C-4, and amino-N attached at C-4 of the pyrimidine are derived from N-1, C-2 and N-3 of the imidazole ring of histidine and the three carbon unit of C-6, C-5 and C-7 is originated from C-1, C-2 and C-3 of ribose.

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Conversion of Vitamim K_1 into Menaquinone-4 in Rat Brain and Plasma

Midori MIURA, Hidekazu HIRAIKE, Mieko KIMURA, Yoshinori ITOKAWA

Article type: Article
1990 Volume 64 Issue 8 Pages 459-462
Published: August 25, 1990
Released on J-STAGE: March 17, 2018

DOIhttps://doi.org/10.20632/vso.64.8_459

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There have been some suggestions as to how to prevent babies from vitamin K deficiency. However, the endogenous form of vitamin K is not known yet. Also it is not known whether vitamin K_1 is more effective than K_2 (MK_n) or vice versa. It has been recommended by the American Academy of Pediatrics that K_1 should be administered parenterally to all newborn infants as prophylaxis. In contrast to that, in Japan, K_2 (MK-4) is generally administered as injection or syrup for babies. In this study, to find out the change of vitamin Ks in plasma and brain tissue, we measured the concentrations of K_1 and MK-4 in K_1 and MK-4 administered and control rats. In brain tissue of control group, MK-4 level was 0.55×10^<-3> nmol/g and K_1 was not detected (<5 ×10^<-4> nmol/g). K_1 and MK-4 levels in plasma of control rats were below the detection limits. In K_1 administered group, MK-4 concentrations were significantly higher in both plasma and brain tissue than those in control. On the other hand, K_1 was not detected in MK-4 administered group. We suppose K_1 may be changed to MK-4 but MK-4 is not changed to K_1, so that MK-4 may be more preferable than K_1. Judging from these points, MK-4 should be prefered as prophylactic vitamin K therapy to babies.

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α-Tocopherol Production by an Analog-resistant Strain of Euglena gracilis Z

[in Japanese], [in Japanese]

Article type: Article
1990 Volume 64 Issue 8 Pages 463-464
Published: August 25, 1990
Released on J-STAGE: March 17, 2018

DOIhttps://doi.org/10.20632/vso.64.8_463

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[title in Japanese]

[in Japanese]

Article type: Article
1990 Volume 64 Issue 8 Pages 465-466
Published: August 25, 1990
Released on J-STAGE: March 17, 2018

DOIhttps://doi.org/10.20632/vso.64.8_465

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[title in Japanese]

[in Japanese]

Article type: Article
1990 Volume 64 Issue 8 Pages 466-468
Published: August 25, 1990
Released on J-STAGE: March 17, 2018

DOIhttps://doi.org/10.20632/vso.64.8_466

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[title in Japanese]

[in Japanese], [in Japanese]

Article type: Article
1990 Volume 64 Issue 8 Pages 469-471
Published: August 25, 1990
Released on J-STAGE: March 17, 2018

DOIhttps://doi.org/10.20632/vso.64.8_469

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[title in Japanese]

[in Japanese]

Article type: Article
1990 Volume 64 Issue 8 Pages 471-472
Published: August 25, 1990
Released on J-STAGE: March 17, 2018

DOIhttps://doi.org/10.20632/vso.64.8_471

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[title in Japanese]

[in Japanese]

Article type: Article
1990 Volume 64 Issue 8 Pages 472-474
Published: August 25, 1990
Released on J-STAGE: March 17, 2018

DOIhttps://doi.org/10.20632/vso.64.8_472

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