Menaquinone-4 amplified glucose-stimulated insulin secretion via the activation of Epac.

Novel physiological functions of selected vitamins and beneficial food constituents have been studied using experimental animals, cell culture system, and human subjects.
1) Novel physiological functions of vitamin K and biotin; (a) clarification of role of menaquinone-4, a type of vitamin K2 in brain, kidney, and testis, (b) clarification of molecular mechanisms involved in the beneficial role of dietary biotin on lifestyle-related diseases.
2) Clarification of physiological functions of naturally occurring isoprenyl compounds and tryptophan metabolites via xenobiotics receptors.
3) Clarification of the relationship of single nucleotide polymorphism in human bitter taste receptors with the individual hepatic nutrient metabolism.
4) Beneficial activity of fermented rice bran and wheat bran products on lifestyle-related diseases in stroke-prone spontaneously hypertensive rats, senescence accelerated mice and genetically modified mice.
5) Elucidation of the effects of food ingredients on renal function and blood pressure.



Vitamin K, biotin, tryptophan metabolites, rice bran, glucose metabolism, lipid metabolism, bitter taste receptor


    Hitoshi Shirakawa(Professor)

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    Yusuke OHSAKI(Assistant Professor)

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    Halima SULTANA(Assistant Professor)

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