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Volume 87, Issue 12
Displaying 1-8 of 8 articles from this issue
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Katsushi KoyamaArticle type: Article
2013 Volume 87 Issue 12 Pages 659-664
Published: December 25, 2013
Released on J-STAGE: August 10, 2017
JOURNAL FREE ACCESSThere are a number of large-scale clinical studies which were implemented for elucidating efficacy of vitamins. In them, however we can find quite a few studies which are inappropriate for using as trustable evidence. Actually, in these studies endpoints were not set suitably for participants' pathophysiological aspects intervened by vitamins supplementation. Furthermore, setting of vitamin intervention strategy according to participants' metabolic feature in which vitamins exert an effect as a coenzyme seems unfavouralbe. Thus, clinical practitioners (a user of the evidence) need to understand various issues which the mentioned large-scale studies should involve. It is expected that research methods using vitamins are making progress in the future.View full abstractDownload PDF (596K) -
Akihito IshigamiArticle type: Article
2013 Volume 87 Issue 12 Pages 665-668
Published: December 25, 2013
Released on J-STAGE: August 10, 2017
JOURNAL FREE ACCESSVitamin C (VC, L-ascorbic acid) is a water-soluble vitamin that functions as an electron donor to reduce reactive oxygen species such as superoxide and hydroxyl radicals. VC is also a cofactor for numerous biosynthetic enzymes such as prolyl and lysyl hydroxylases for procollagen hydroxylation. VC is synthesized mainly in the liver of most mammalian species including mice and rats. However, humans, primates, and guinea pigs are unable to synthesize VC in vivo. VC is thought to be required for the maintenance of pregnancy and fetal development. However, the effects of an VC's absence on embryonic and neonatal development during pregnancy have not been determined. Therefore, we examined pregnant mice completely or partially deprived of VC to test embryonic and neonatal development by using SMP30/GNL knockout mice which are unable to synthesize VC in vivo. As a result, we found that an absence or a low intake of VC during pregnancy induced multiple abnormalities in the developing tissues of SMP30/GNL knockout mice. In another study, we also found that these SMP30/GNL knockout mice were shorter in life-span than the wild-type mice when fed a VC low diet (about 2.5% a day of VC). Therefore, a diet that supplies an adequate amount of VC is essential to provide optimal conditions for fetal and neonatal health and to avoid a life-shortening deficiency.View full abstractDownload PDF (496K) -
Keiko YamamotoArticle type: Article
2013 Volume 87 Issue 12 Pages 669-677
Published: December 25, 2013
Released on J-STAGE: August 10, 2017
JOURNAL FREE ACCESSVitamin D actions are expressed through binding to specific proteins related to metabolism, transport and transcription. The proteins are cytochrome P450 (CYP) which is vitamin D hydroxylase, vitamin D binding protein (DBP) which is a plasma carrier protein of vitamin D, and vitamin D receptor (VDR) which is gene transcription factor. Vitamin D directly binds to these proteins. In recent years, crystal structures of CYP, DBP and VDR were analyzed and binding modes of vitamin D to these proteins were also shown. In this review, I summarize the crystal structures of CYP2R1/vitamin D_3, CYP24A1/detergent, DBP/25-hydroxyvitmain D_3 and VDR/ligand complexes. Crystal structures showed that the hydroxyl group of vitamin D forms a specific hydrogen bond with the protein and the remaining part of vitamin D interacts with hydrophobic residues of the protein. Interestingly, vitamin D in the complexes adopted specific conformation to adapt to the binding site of each protein. The information obtained from the structural analyses of vitamin D and related proteins is strongly expected to open an interesting new perspective to develop alternative drugs for treatment of vitamin D-related diseases.View full abstractDownload PDF (1089K) -
Kimitaka TakitaniArticle type: Article
2013 Volume 87 Issue 12 Pages 678-684
Published: December 25, 2013
Released on J-STAGE: August 10, 2017
JOURNAL FREE ACCESSVitamin E has an important role for prevention against lipid peroxidation in several pathological conditions. α-Tocopherol transfer protein (α-TTP) binds selectively α-tocopherol, and regulates α-tocopherol levels in the plasma. Moreover, α-TTP is known to play a critical role in the maintenance of pregnancy and in protecting against lipid peroxidation in the central nervous system. However, there are few reports regarding the regulation of α-TTP expression. We have conducted the promoter analysis of human α-TTP gene, and have examined vitamin E status and α-TTP expression in several pathological conditions including type 2 diabetes and nonalcoholic fatty liver disease (NAFLD). Human α-TTP gene is transcriptionally regulated through liver X receptor (LXR) signaling, which is a member of nuclear receptor superfamily and modulates lipid metabolism and energy metabolism. Hepatic α-TTP expression was altered in pathological conditions including type 2 diabetes and NAFLD, and might affect α-tocopherol status. Investigation of the regulation of α-TTP expression may contribute to further clarification of vitamin E status in pathological conditions and further understanding of the antioxidant mechanisms of vitamin E.View full abstractDownload PDF (823K) -
Hideyuki HayashiArticle type: Article
2013 Volume 87 Issue 12 Pages 685-690
Published: December 25, 2013
Released on J-STAGE: August 10, 2017
JOURNAL FREE ACCESSDownload PDF (582K) -
Yoshihisa Hirota, Kimie Nakagawa, Yoshitomo Suhara, Toshio OkanoArticle type: Article
2013 Volume 87 Issue 12 Pages 691-695
Published: December 25, 2013
Released on J-STAGE: August 10, 2017
JOURNAL FREE ACCESSDownload PDF (649K) -
Tomoya Kitakaze, Naoki Harada, Ryoichi YamajiArticle type: Article
2013 Volume 87 Issue 12 Pages 696-699
Published: December 25, 2013
Released on J-STAGE: August 10, 2017
JOURNAL FREE ACCESSDownload PDF (495K) -
Article type: Bibliography
2013 Volume 87 Issue 12 Pages 700-705
Published: December 25, 2013
Released on J-STAGE: August 10, 2017
JOURNAL FREE ACCESSDownload PDF (602K)
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