EXOGENOUS GM3 GANGLIOSIDE STIMULATES PROCESS FORMATION AND GLYCOPROTEIN RELEASE BY CULTURED BOVINE OLIGODENDROCYTES

Isolated adult bovine oligodendrocytes maintained in vitro for 10 days were treated for 1 day with 50-mu-g/ml of GM3 ganglioside (NeuNAc-alpha-2-3Gal-beta-1-4Glc-beta-1-l'ceramide) in serum-free culture medium. The treated oligodendrocytes had significantly longer processes with more branching than control cells in the same medium without GM3. The treatment also stimulated the release of a series of 22-100-kDa, [H-3]glucosamine-labeled glycoproteins into the culture medium. Treatment of oligodendrocytes maintained in vitro for 50 days with GM3 for 1 day resulted in a thickening of the processes and the appearance of many fine branches on existing processes as well as a similar stimulation of glycoprotein release into the medium.