Jump to main content
Jump to site search

Issue 7, 2011
Previous Article Next Article

Dietary vitamin K alleviates the reduction in testosterone production induced by lipopolysaccharide administration in rat testis

Author affiliations

Abstract

Vitamin K is essential for the posttranslational modifications of blood coagulation factors and proteins present in the bone matrix. Vitamin K is distributed not only in the liver and bones but is also abundant in the brain, kidney, and gonadal tissues. However, the function of extra-hepatic/bone vitamin K has not been fully elucidated. Previously, we observed that dietary supplementation with vitamin K suppresses inflammation, and vitamin K deficiency decreases testicular testosterone production in rats. Here, we examined whether the dietary vitamin K state affects testicular steroidogenesis in lipopolysaccharide (LPS)-treated rats because vitamin K has anti-inflammatory activity. Male Wistar rats were fed either vitamin K-free or control diets for 35 d, and then intraperitoneally administered LPS (0.5 mg kg−1 body weight) to induce inflammation for 6 h. Vitamin K deficiency symptoms were not observed in the vitamin K-free diet group; however, the vitamin K levels in the testis were significantly lower in the vitamin K-free diet group than in the control diet group. After LPS treatment, plasma testosterone levels were significantly reduced in the vitamin K-free diet group compared with the control diet group. Testicular mRNA and protein levels of Cyp11a, a rate-limiting enzyme in steroidogenesis, corresponded to plasma testosterone levels. However, plasma luteinizing hormone levels were unaffected by diet and LPS. Phosphorylated nuclear factor κB p65 in the testis was significantly increased in the LPS-treated, vitamin K-free diet group compared with control. These results indicate that dietary vitamin K affects testicular vitamin K levels and ameliorates the LPS-induced reduction in testicular testosterone synthesis. Testicular vitamin K might facilitate the inhibition of inflammation signal transduction and maintain steady levels of testosterone.

Graphical abstract: Dietary vitamin K alleviates the reduction in testosterone production induced by lipopolysaccharide administration in rat testis

Back to tab navigation

Publication details

The article was received on 18 Apr 2011, accepted on 27 May 2011 and first published on 13 Jun 2011


Article type: Paper
DOI: 10.1039/C1FO10058K
Citation: Food Funct., 2011,2, 406-411
  •   Request permissions

    Dietary vitamin K alleviates the reduction in testosterone production induced by lipopolysaccharide administration in rat testis

    N. Takumi, H. Shirakawa, Y. Ohsaki, A. Ito, T. Watanabe, P. E. Giriwono, T. Sato and M. Komai, Food Funct., 2011, 2, 406
    DOI: 10.1039/C1FO10058K

Search articles by author

Spotlight

Advertisements