Influence of reduced cholesterol synthesis on the activity of cerebroside sulfotransferase in cultured glioblastoma cells treated with estradiol.

Cultured glioblastoma cells were inoculated with estradiol in concentrations of 0.5--10 microliter/ml medium in order to check the effect of this hormone on the activity of cerebroside sulfotransferase, an enzyme whose activity is strongly related to myelination. Thereby we could show that the cerebroside-sulfotransferase activity increases to a value of 200% of normal. Concomitant to this effect, the cholesterol content of the membrane bearing cerebroside sulfotransferase activity decreases to 60% of normal. The effect is fully reversible: after 48 h, cholesterol synthesis as well as cerebroside sulfotransferase activity reach normal values again. We suggest that cerebroside sulfotransferase activity is modulated by the changing cholesterol/phospholipid ratio in the cells during the inoculation period.