Oxygenation of desmosterol and cholesterol in cell cultures.
Cells-Cultured, Cholesterol: me, Chromatography-High-Pressure-Liquid, Desmosterol: me, Fibroblasts, Hamsters, Hydroxycholesterols: me, Lung: cy, me, Mice, Oxygen: me, SUPPORT-U-S-GOVT-P-H-S, Time-Factors
J Lipid Res 1990 Dec; 31(12):2179-85.
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.
Saucier, S E.; Kandutsch, A A.; Gayen, A K.; Nelson, J A.; and Spencer, T A., " Oxygenation of desmosterol and cholesterol in cell cultures." (1990). Faculty Research 1990 - 1999. 59.