Incorporation of tritiated galactose into galactocerebroside by cultured rat oligodendrocytes: effects of cyclic adenosine 3',5'-monophosphate analogues.

Cells dissociated from the forebrains of 21-day-old rats were enriched in oligodendroglia by Percoll gradient centrifugation, seeded on polylysine-coated surfaces, and cultured in a serum-containing medium. Incorporation by the cultures of tritium from D-[3H]galactose into the galactosyl residue of galactocerebroside (galC) increased in an almost linear fashion for 48 h with 1-8 muCi of D-[3H]galactose (30 mCi/mumol) per milliliter medium. Treatment for 2 days (day 1-3 after seeding) with 10(-4) M or 10(-3) M dibutyryl cyclic adenosine 3',5'-monophosphate (db cyclic AMP) or 10(-4) M 8-bromo cyclic AMP stimulated galC radiolabelling. Incorporation of D-[3H]galactose into galC during a terminal 48-h radiolabelling period was not stimulated when the cells were continuously treated with these cyclic AMP analogues for 8 rather than 2 days.