Abstract
It is generally accepted that the availability of vitamin K in vivo depends on its homologues, the biological activities of which would differ among organs. To test this hypothesis, we examined the uptake, metabolism, and utilization of menaquinone-4 (MK-4) and phylloquinone (PK) using 18O-labeled compounds in two cultured human cell lines (HepG2 and MG-63). Lipid extracts were prepared from the cells and media after 1, 3, and 6 h of incubation. The detection of the vitamin K analogues (18O-, 16O-quinone, and epoxide forms) was carried out with LC-APCI-MS/MS as previously reported. The 18O of vitamin K was replaced with atmospheric 16O2 during the formation of vitamin K epoxide with a carboxylative catalytic reaction. As a result, a significant difference was observed between MK-4 and PK in the amounts taken up into the cells. The 18O-labeled MK-4 was rapidly and remarkably well absorbed into the cells and metabolized to the epoxide form via a hydroquinone form as compared to the 18O-labeled PK. The difference in uptake of MK-4 and PK was not affected by treatment with warfarin although the metabolism of both compounds was markedly inhibited. This methodology should be utilized to clarify some of the actions of vitamin K in target cells and facilitate the development of new vitamin K drugs.
| Original language | English |
|---|---|
| Pages (from-to) | 6601-6607 |
| Number of pages | 7 |
| Journal | Bioorganic and Medicinal Chemistry |
| Volume | 14 |
| Issue number | 19 |
| DOIs | |
| Publication status | Published - 2006 Oct 1 |
| Externally published | Yes |
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Keywords
- LC-APCI-MS/MS
- Menaquinone-4
- Metabolism
- Phylloquinone
- Uptake
- Vitamin K cycle
ASJC Scopus subject areas
- Biochemistry
- Molecular Biology
- Organic Chemistry
- Drug Discovery
- Pharmaceutical Science
Cite this
Comparative uptake, metabolism, and utilization of menaquinone-4 and phylloquinone in human cultured cell lines. / Suhara, Yoshitomo; Murakami, Aya; Nakagawa, Kimie; Mizuguchi, Yukari; Okano, Toshio.
In: Bioorganic and Medicinal Chemistry, Vol. 14, No. 19, 01.10.2006, p. 6601-6607.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Comparative uptake, metabolism, and utilization of menaquinone-4 and phylloquinone in human cultured cell lines
AU - Suhara, Yoshitomo
AU - Murakami, Aya
AU - Nakagawa, Kimie
AU - Mizuguchi, Yukari
AU - Okano, Toshio
PY - 2006/10/1
Y1 - 2006/10/1
N2 - It is generally accepted that the availability of vitamin K in vivo depends on its homologues, the biological activities of which would differ among organs. To test this hypothesis, we examined the uptake, metabolism, and utilization of menaquinone-4 (MK-4) and phylloquinone (PK) using 18O-labeled compounds in two cultured human cell lines (HepG2 and MG-63). Lipid extracts were prepared from the cells and media after 1, 3, and 6 h of incubation. The detection of the vitamin K analogues (18O-, 16O-quinone, and epoxide forms) was carried out with LC-APCI-MS/MS as previously reported. The 18O of vitamin K was replaced with atmospheric 16O2 during the formation of vitamin K epoxide with a carboxylative catalytic reaction. As a result, a significant difference was observed between MK-4 and PK in the amounts taken up into the cells. The 18O-labeled MK-4 was rapidly and remarkably well absorbed into the cells and metabolized to the epoxide form via a hydroquinone form as compared to the 18O-labeled PK. The difference in uptake of MK-4 and PK was not affected by treatment with warfarin although the metabolism of both compounds was markedly inhibited. This methodology should be utilized to clarify some of the actions of vitamin K in target cells and facilitate the development of new vitamin K drugs.
AB - It is generally accepted that the availability of vitamin K in vivo depends on its homologues, the biological activities of which would differ among organs. To test this hypothesis, we examined the uptake, metabolism, and utilization of menaquinone-4 (MK-4) and phylloquinone (PK) using 18O-labeled compounds in two cultured human cell lines (HepG2 and MG-63). Lipid extracts were prepared from the cells and media after 1, 3, and 6 h of incubation. The detection of the vitamin K analogues (18O-, 16O-quinone, and epoxide forms) was carried out with LC-APCI-MS/MS as previously reported. The 18O of vitamin K was replaced with atmospheric 16O2 during the formation of vitamin K epoxide with a carboxylative catalytic reaction. As a result, a significant difference was observed between MK-4 and PK in the amounts taken up into the cells. The 18O-labeled MK-4 was rapidly and remarkably well absorbed into the cells and metabolized to the epoxide form via a hydroquinone form as compared to the 18O-labeled PK. The difference in uptake of MK-4 and PK was not affected by treatment with warfarin although the metabolism of both compounds was markedly inhibited. This methodology should be utilized to clarify some of the actions of vitamin K in target cells and facilitate the development of new vitamin K drugs.
KW - LC-APCI-MS/MS
KW - Menaquinone-4
KW - Metabolism
KW - Phylloquinone
KW - Uptake
KW - Vitamin K cycle
UR - http://www.scopus.com/inward/record.url?scp=33747159665&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=33747159665&partnerID=8YFLogxK
U2 - 10.1016/j.bmc.2006.06.004
DO - 10.1016/j.bmc.2006.06.004
M3 - Article
VL - 14
SP - 6601
EP - 6607
JO - Bioorganic and Medicinal Chemistry
JF - Bioorganic and Medicinal Chemistry
SN - 0968-0896
IS - 19
ER -