- 著者
- Kazuhiro YAMADA Tetsunori KAWATA Masahiro WADA Kazumi MORI Hiroko TAMAI Nobuo TANAKA Tadahiro TADOKORO Takamasa TOBIMATSU Tetsuo TORAYA Akio MAEKAWA
- 出版者
- Center for Academic Publications Japan
- 雑誌
- Journal of Nutritional Science and Vitaminology (ISSN:03014800)
- 巻号頁・発行日
- vol.53, no.2, pp.95-101, 2007 (Released:2008-01-10)
- 参考文献数
- 41
- 被引用文献数
- 7 9
We have previously reported that rats fed on a vitamin B12 (B12)-deficient diet containing 180 g soybean protein per kg diet showed marked histologic damage in their testes. In this paper, we report the effect of B12-deficiency on B12-dependent methionine synthase in the rats' testes and the effect of methionine supplementation of the diet on testicular damage. Rats were fed the soybean protein-based B12-deficient diet for 120 d. We confirmed that those rats were in serious B12-deficiency by measuring urinary methylmalonic acid excretion and B12 content in tissues. Methionine synthase activity in the testis of the B12-deficient rats was less than 2% of that in B12-supplemented (control) rats. To complement disrupted methionine biosynthesis, methionine was supplied in the diet. A supplement of 5 g D,L-methionine per kg diet to the B12-deficient diet did not affect urinary methylmalonic acid excretion of B12-deficient rats. The testicular histology of rats fed the methionine-supplemented B12-deficient diet was almost indistinguishable from that of control rats. Thus, we conclude that the lowered testicular methionine synthase activity is the primary cause of the histologic damage due to B12-deficiency and that methionine supplementation to the diet can reduce the damage. These findings would indicate the importance of the methionine synthase activity, especially for testicular function.
- 著者
- Ulala FUNADA Masahiro WADA Tetsunori KAWATA Nobuo TANAKA Tadahiro TADOKORO Akio MAEKAWA
- 出版者
- Japan Society for Bioscience, Biotechnology, and Agrochemistry
- 雑誌
- Bioscience, Biotechnology, and Biochemistry (ISSN:09168451)
- 巻号頁・発行日
- vol.64, no.10, pp.2053-2058, 2000 (Released:2005-02-03)
- 参考文献数
- 36
- 被引用文献数
- 3
Cyanocobalamin, deoxyadenosylcobalamin and methylcobalamin were separately administered to mice sensitized with the ovalbumin antigen to investigate the allergic response. The serum IgE and pulmonary histamine concentrations were significantly lower in all cobalamin (Cbl)-administered groups. The production of interleukin (IL)-2 and IL-4 in splenocytes was also lower in all Cbl-administered groups. These results show that Cbls were effective in mitigating allergic reactions and IL-2 production. CD3+CD28+ (CD28 is an accessory molecule related to IL-2 production) and CD4+CD28+ in splenocytes were higher in all the Cbl-administered groups. However, CD3+CD28-, CD4+CD28- and CD5+CD25- (CD25: IL-2 Rα/p55) were lower in the Cbl-administered groups. In addition, Cbl specifically inhibited the cellular phosphorylation of tyrosine induced by ovalbumin sensitization. These results indicate that the signal in a cell by CD 28 was restrained by Cbl. We infer that Cbl administration significantly reduced the IL-2 concentration, and secondarily the IL-4, IgE and histamine concentrations.