VITAMINS

Mechanism of Bactericidal Action of Ascorbic Acid on Escherichia coli

Akira MURATA, Reiko KINOSHITA, Yumi INOUE, Fumio KATO

Article type: Article
1991 Volume 65 Issue 9 Pages 439-445
Published: September 25, 1991
Released on J-STAGE: March 17, 2018

DOIhttps://doi.org/10.20632/vso.65.9_439

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The in vitro bactericidal action of L-ascorbic acid (AsA) on bacteria in the presence of a trace level of Cu^<2+> was previously reported. This paper describes the possible mechanism of the bactericdal action of AsA on Escherichia coli. Bubbling oxygen through the reaction mixture and the addition of H_2O_2 or transition metal ions to the reaction mixture enhanced the bactericidal action of AsA. On the other hand, nitrogen bubbling and the addition of reducing agents, chelating agents, radical scavengers or catalase inhibited the bactericidal action. The results indicate that oxygen radicals are involved in the bactericidal action of AsA. The in vitro single-atrand scission in bacterial DNA by the oxygen radicals was observed. In addition, the alteration of the bacterial cell surface by the oxygen radicals was suggested. Possible mechanisms of the bactericidal action of AsA were discussed.

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Extracorporeal Shockwave Lithotripsy (ESWL) for Urolithiasis : Evaluation of Tissue Injury by Measuring Serum and Urine 28-kDa Calbindin-D

Soichiro HASEGAWA, Kanefusa KATO, Munehisa TAKASHI, Yuanyuan ZHU, Keii ...

Article type: Article
1991 Volume 65 Issue 9 Pages 447-452
Published: September 25, 1991
Released on J-STAGE: March 17, 2018

DOIhttps://doi.org/10.20632/vso.65.9_447

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28-kDa Calbindin-D is a vitamin D dependent calcium binding protein which is mainly localized in the distal renal tubules and central nervous tissue in human tissues. To clarify the extent to which the extracorporeal shockwave lithotripsy (ESWL) for urolithiasis damages renal tissues, we immunoassayed 28-kDa Calbindin-D in the serum and urine from patients with renal stone (n=21) and ureteral stone (n=18) before and after (0, 2 and 24 hours) ESWL. The concentrations of 28-kDa Calbindin-D were enhanced significantly after ESWL as follows. 1) In patients with renal stone : 0, 2 and 24 hours after ESWL in serum ; 0 and 2 hours after ESWL in urine. Serum concentrations of 28-kDa Calbindin-D in patients with renal stone were significantly higher than those of ureteral stone at 0, 2 and 24 hours after ESWL. In contrast, no significant difference was found in the urine concentration of 28-kDa Calbindin-D between both patients. These findings suggest that (1) ESWL for renal stone might damage distal renal tubules and that (2) ESWL for ureteral stone might also cause a distal renal tubular injury, but specific marker reflects distal renal tubular injury by ESWL for urolithiasis.

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Mechanism of Antioxidant Reaction of Vitamin E

Aya KURANAKA, Kouhei SAWADA, Umpei NAGASHIMA, Shin-ichi NAGAOKA, Kazuo ...

Article type: Article
1991 Volume 65 Issue 9 Pages 453-458
Published: September 25, 1991
Released on J-STAGE: March 17, 2018

DOIhttps://doi.org/10.20632/vso.65.9_453

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A kinetic and ab initio study of the antioxidant effect of vitamin E derivatives (tocopherols) has been carried out. The second-order rate constants, k_s, for the reaction of tocopherols with a substituted phenoxyl radical in ethanol were measured with a stopped-flow spectrophotometer. k_s increases as the total electron-donating capacity of the alkyl substituents on the aromatic ring of tocopherol increases. A substantial deuterium kinetic isotope effect on k_s is observed. The first ionization energies (I. P. ) of tocopherols were calculated with the ab initio method. A plot of log k_s vs. I. P. is found to be linear. From these results, it is considered that both of the charge transfer and the proton tunneling play important roles in the antioxidant reaction of tocopherol. The transition state in this reaction has the property of the charge-transfer intermediate. The proton tunneling takes place below the transition state.

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Estimated Conversion Efficiency of Tryptophan : Nicotinamide using an Activity Ratio of 3-Hydroxyanthranilate 3,4-Dioxygenase to Aminocarboxymuconate-semialdehyde Decarboxylase in Birds

Hiroshi TAGUCHI, Motohiko HAYANO, Katsumi SHIBATA

Article type: Article
1991 Volume 65 Issue 9 Pages 459-460
Published: September 25, 1991
Released on J-STAGE: March 17, 2018

DOIhttps://doi.org/10.20632/vso.65.9_459

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In order to estimate the conversion efficiency of tryptophan-nicotinamide in chicken, crow, pigeon, and sparrow, the liver 3-hydroxyanthranilate 3, 4-dioxygenase (3-HAOase, EC 1. 13. 11. 6) and aminocarboxymuconate-semialdehyde decarboxylase (ACMSDase ; EC 4. 1. 1. 45) activities were measured. Activity ratio of 3-HAOase/ACMSDase in the livers of chiken, crow pigeon, and sparrow were 69.5, 18.5, 59.2 and 19.0, respectively. The higher value means the higher conversion of tryptophan-nicotinamide. For example, this value is around 280 in rats, which can be efficiently used tryptophan as provitamin of nicotinamide and 5 in cats which can hardly used. Therefore, it was found that chicken and pigeon can be used tryptophan as provitamin of nicotinamide, however, crow and sparrow can be hardly used.

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[title in Japanese]

[in Japanese]

Article type: Article
1991 Volume 65 Issue 9 Pages 461-
Published: September 25, 1991
Released on J-STAGE: March 17, 2018

DOIhttps://doi.org/10.20632/vso.65.9_461_1

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[title in Japanese]

[in Japanese], [in Japanese], [in Japanese], [in Japanese]

Article type: Article
1991 Volume 65 Issue 9 Pages 461-462
Published: September 25, 1991
Released on J-STAGE: March 17, 2018

DOIhttps://doi.org/10.20632/vso.65.9_461_2

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[title in Japanese]

[in Japanese]

Article type: Article
1991 Volume 65 Issue 9 Pages 462-464
Published: September 25, 1991
Released on J-STAGE: March 17, 2018

DOIhttps://doi.org/10.20632/vso.65.9_462

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[title in Japanese]

[in Japanese], [in Japanese], [in Japanese], [in Japanese]

Article type: Article
1991 Volume 65 Issue 9 Pages 464-
Published: September 25, 1991
Released on J-STAGE: March 17, 2018

DOIhttps://doi.org/10.20632/vso.65.9_464

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[title in Japanese]

[in Japanese]

Article type: Article
1991 Volume 65 Issue 9 Pages 465-466
Published: September 25, 1991
Released on J-STAGE: March 17, 2018

DOIhttps://doi.org/10.20632/vso.65.9_465

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[title in Japanese]

[in Japanese]

Article type: Article
1991 Volume 65 Issue 9 Pages 466-467
Published: September 25, 1991
Released on J-STAGE: March 17, 2018

DOIhttps://doi.org/10.20632/vso.65.9_466

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[title in Japanese]

[in Japanese]

Article type: Article
1991 Volume 65 Issue 9 Pages 467-468
Published: September 25, 1991
Released on J-STAGE: March 17, 2018

DOIhttps://doi.org/10.20632/vso.65.9_467

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[title in Japanese]

[in Japanese]

Article type: Article
1991 Volume 65 Issue 9 Pages 468-470
Published: September 25, 1991
Released on J-STAGE: March 17, 2018

DOIhttps://doi.org/10.20632/vso.65.9_468

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[title in Japanese]

[in Japanese]

Article type: Article
1991 Volume 65 Issue 9 Pages 470-471
Published: September 25, 1991
Released on J-STAGE: March 17, 2018

DOIhttps://doi.org/10.20632/vso.65.9_470

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