| Autor: |
Saucier SE; Jackson Laboratory, Bar Harbor, ME 04609., Kandutsch AA, Gayen AK, Nelson JA, Spencer TA |
| Jazyk: |
angličtina |
| Zdroj: |
Journal of lipid research [J Lipid Res] 1990 Dec; Vol. 31 (12), pp. 2179-85. |
| Abstrakt: |
In order to determine whether hydration of the delta 24 bond of desmosterol contributes to the formation of the regulatory oxysterol, 25-hydroxycholesterol, [3H]desmosterol was incubated with two cultured cell lines and the labeled products were analyzed. Small amounts of 25-hydroxycholesterol were formed with Chinese hamster lung (Dede) cell cultures, but not with mouse fibroblast (L) cell cultures. Apparently, desmosterol was converted into cholesterol, a process that does not occur in L cells, before 25-hydroxycholesterol takes place. No reliable evidence could be obtained for hydration of the delta 24 bond or for the reverse reaction upon incubation of [3H]25-hydroxycholesterol. Oxygenation of desmosterol occurred in both Dede and L cell cultures to give a mixture of 24(R)- and 24(S)-25-epoxy-cholesterol. This reaction, along with the production of 7-oxygenated sterols, may account for low levels of HMG-CoA reductase repressor activity previously found to be associated with delta 24 sterols. |
| Databáze: |
MEDLINE |
| Externí odkaz: |
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