VITAMINS

Biochemical and Molecular Biological Studies of Arachidonate 12-Lipoxygenases

Yoshitaka TAKAHASHI, Hiroshi SUZUKI, Toshiya ARAKAWA, Tanihiro YosHIIM ...

Article type: Article
1993 Volume 67 Issue 1 Pages 1-16
Published: January 25, 1993
Released on J-STAGE: March 30, 2018

DOIhttps://doi.org/10.20632/vso.67.1_1

JOURNAL OPEN ACCESS

Show abstractHide abstract

Arachidonate 12-lipoxygenase is a dioxygenase which incorporates one molecule of oxygen into arachidonic acid and produces 12S-hydroperoxy-5, 8, 10, 14-eicosate-traenoic acid. The enzyme has been found in various tissues of many animal species. Two types of 12-lipoxygenase are distinguishable in terms of substrate specificity. The leukocyte-type enzyme is active not only with arachidonic acid and other C_<20> acids but also with C_<18> acids such as linoleic and linolenic acids. In contrast, the platelet-type enzyme is almost inactive with C_<18> acids. The two enzymes are also distinct in terms of immunogenicity, heat stability and reaction time course. Furthermore, the cDNAs for porcine leukocyte and human platelet 12-lipoxygenases do not cross-hybridize each other. The substrate specificity, immunogenicity, primary structure and genomic organization of porcine leukocyte 12-lipoxygenase are closer to those of rabbit reticulocyte 15-lipoxygenase than those of human platelet 12-lipoxygenase. The leukocyte-type enzyme has also been found in porcine pituitary, bovine trachea, canine brain, and human adrenal glomerulosa cells, but the platelet type enzyme has so far been found only in platelets of several animal species.

View full abstract

Download PDF (1559K)
α-Tocophorol Levels in Plasma, Blood Cells, and Buccal Mucosal Cells in Elderly Subjects

Hiroshi TAMAI, Takuya TANABE, Tohru OGIHARA, Makoto MINO, Junta TAKAMA ...

Article type: Article
1993 Volume 67 Issue 1 Pages 17-21
Published: January 25, 1993
Released on J-STAGE: March 30, 2018

DOIhttps://doi.org/10.20632/vso.67.1_17

JOURNAL OPEN ACCESS

Show abstractHide abstract

Measurement of α-tocopherol in plasma, red blood cells, platelets, mononuclear cells, polymorphonuclear cells, and buccal mucosal cells was made in the institutionalized 39 elderly subjects aged from 55 to 89 years. The levels were compared with those in 20 healthy young adult volunteers (22-38 years). The tocopherol level in platelets, mononuclear cells, polymorphonuclear cells, and buccal mucosal cells was lower in elderly subjects than in young adults, while no significant differences were observed in plasma- and RBC-tocopherol levels, and the plasma tocopherol/total lipid ratios between two groups. Daily dietary intakes of α-tocopherol, which was calculated from the dietary menues, were lower in the subjects in the institution, as compared with the Recommended Dietary Allowances in Japan (8 mg for males and 7 mg for females, as α-tocopherol equivalent) for adults.

View full abstract

Download PDF (433K)
Annual Changes of Niacin Intake and Effects of Life Conditions on Niacin Intake Calculated on The Basis of The National Nutrition Survey

Akiko WAKAMURA, Kaoru KAMIOKA, Ryokuero SUZUE, Fumiko HIRAHARA

Article type: Article
1993 Volume 67 Issue 1 Pages 23-29
Published: January 25, 1993
Released on J-STAGE: March 30, 2018

DOIhttps://doi.org/10.20632/vso.67.1_23

JOURNAL OPEN ACCESS

Show abstractHide abstract

Annual changes of niacin intake per caputa per day were calculated on the basis of the results of the National nutrition survey form 1970 to 1989 using the Weighted average tables of niacin and also tryptophan contents of protein in foods. The widely adopted convention that 60 mg of trytophan can be taken as equivalent to 1 mg dietary niacin was used. The mean value of the daily niacin intake was 32.5 mg and it exceeded the Japanese Recommended Dietary Allowance of niacin (about 17 mg). Major sources of niacin from food were fishes, cereals and meats. In addition, the investigation were carried out to be clarified the influential factors on niacin intake. From these studies, it was clarified that the intake of niacin may be considerably high even for the low-income families.

View full abstract

Download PDF (570K)
[title in Japanese]

[in Japanese]

Article type: Article
1993 Volume 67 Issue 1 Pages 31-32
Published: January 25, 1993
Released on J-STAGE: March 30, 2018

DOIhttps://doi.org/10.20632/vso.67.1_31

JOURNAL OPEN ACCESS

Download PDF (310K)
[title in Japanese]

[in Japanese]

Article type: Article
1993 Volume 67 Issue 1 Pages 32-33
Published: January 25, 1993
Released on J-STAGE: March 30, 2018

DOIhttps://doi.org/10.20632/vso.67.1_32

JOURNAL OPEN ACCESS

Download PDF (329K)
[title in Japanese]

[in Japanese], [in Japanese]

Article type: Article
1993 Volume 67 Issue 1 Pages 33-34
Published: January 25, 1993
Released on J-STAGE: March 30, 2018

DOIhttps://doi.org/10.20632/vso.67.1_33

JOURNAL OPEN ACCESS

Download PDF (325K)
[title in Japanese]

[in Japanese]

Article type: Article
1993 Volume 67 Issue 1 Pages 34-35
Published: January 25, 1993
Released on J-STAGE: March 30, 2018

DOIhttps://doi.org/10.20632/vso.67.1_34

JOURNAL OPEN ACCESS

Download PDF (273K)

Register with J-STAGE for free!