Sphingolipid metabolism was examined in human promyelocytic leukemia HL-60 cells.
Differentiation of HL-60 cells with 1 α, 25-dihydroxyvitamin D 3 (vitamin D 3; 100 nM) was
accompanied by sphingomyelin turnover. Maximum turnover of [3 H] choline-labeled
sphingomyelin occurred 2 h following vitamin D 3 treatment, with sphingomyelin levels
decreasing to 77±6% of control and returning to base-line levels by 4 h. Ceramide and
phosphorylcholine were concomitantly generated. Ceramide mass levels increased by 55 …