CEREBROSIDE FORMATION IN THE PERIPHERAL NERVOUS-SYSTEM OF NORMAL AND TREMBLER MICE

The formation of cerebrosides by the galactosylation of ceramides was investigated in a microsomal fraction prepared from sciatic nerves of normal and Trembler mice. In the control, cerebroside synthesis is obs erved in the presence of uridine-diphosphate-galactose both from endog enously synthesized [1-C-14]stearoyl-sphingosine (C18-ceramide), and f rom [1-C-14]lignoceroyl-sphingosine (C24-ceramide). Cerebroside format ion is also demonstrated by studying the galactosylation of exogenous ceramides with UDP[1-C-14]galactose. In the mutant, only trace amounts of labeled cerebrosides are formed from labeled stearoyl-sphingosine, whereas with lignoceroyl-sphingosine, no cerebroside synthesis is det ected under conditions allowing their formation in the control. Howeve r, a higher rate of synthesis of short acyl chain-glucosyl ceramides i s observed in the Trembler samples.