Skip NavigationSkip to Content
Return Return to Search Results

Characterization of 3-epi-1 alpha,25-dihydroxyvitamin D-3 involved in 1 alpha,25-dihydroxyvitamin D-3 metabolic pathway in cultured cell lines

  1. Author:
    Masuda, S.
    Kamao, M.
    Schroeder, N. J.
    Makin, H. L. J.
    Jones, G.
    Kremer, R.
    Rhim, J.
    Okano, T.

  2. Author Address

    Masuda S Coll Nursing Art & Sci, Dept Biochem & Physiol 13-71 Kitaoji Cho Akashi Hyogo 6588588 Japan Kobe Pharmaceut Univ, Dept Hyg Sci, Higashinada Ku Kobe Hyogo 6588558 Japan St Bartholomews & Royal London Sch Med & Dent, Dept Clin Biochem London E1 2AD England Queens Univ, Dept Biochem Kingston ON K7L 3N6 Canada Royal Victoria Hosp, Calcium Res Lab Montreal PQ H3A 1A1 Canada NCI, Lab Biochem Physiol Frederick, MD 21702 USA
    1. Year: 2000
  2. Journal: Biological & Pharmaceutical Bulletin
    1. 23
    2. 2
    3. Pages: 133-139
  4. Type of Article: Article
  1. Abstract:

    Using sis different cultured cell models representing osteoblast, intestine, kidney and keratinocyte, we have demonstrated that 1 alpha,25-dihydroxyvitamin D-3 (1 alpha,25(OH)(2)D-3) is metabolized into 3-epi-1 alpha,25(OH)(2)D-3 in vitamin D-target cells. Although differences existed in the amount of 3-epi-1 alpha,25(OH)(2)D-3 formed with different cell types, it was apparent that 1 alpha,25(OH)(2)D-3 was subjected to metabolism both through the C24-oxidation and 3-epimerization pathways. Time course and dose response studies showed that the production of 3-epi-1 alpha,25(OH)(2)D-3 was enzymatic. It is interesting to note that this epimerization proceeded from 3 beta towards 3 or unidirectionally, and this conversion was not inhibited by ketoconazole. These data suggest that cytochrome P450 related enzymes including the 24-hydroxylase would not affect this reaction. The biological activity of J-epi-1 alpha,25(OH)(2)D-3 was found to be lower than the native 1 alpha,25(OH)(2)D-3 in suppressing of proliferation of HL-60 cells, while the affinity of 3-epi-1 alpha,25(OH)(2)D-3 for vitamin D-binding protein was 2.5-fold higher than that of 1 alpha,25(OH)(2)D-3. The results indicate that 3-epimerization may change the pharmacokinetics and catabolism of 1 alpha,25(OH)(2)D-3 in vitamin D-target cells. [References: 22]

    See More

  1. Keywords:

External Sources

  1. No sources found.

Library Notes

  1. No notes added.
NCI at Frederick

You are leaving a government website.

This external link provides additional information that is consistent with the intended purpose of this site. The government cannot attest to the accuracy of a non-federal site.

Linking to a non-federal site does not constitute an endorsement by this institution or any of its employees of the sponsors or the information and products presented on the site. You will be subject to the destination site's privacy policy when you follow the link.

ContinueCancel