The effects of inhibitors of protein synthesis on incorporation of lipids into myelin

Abstract— Following intracranial injections of puromycin, the incorporation of ³H]leucine into brain protein was inhibited by 80 per cent. Conversely, incorporation of ³⁵S]sulphate into sulphatide or 2-³H]glycerol into phosphatidyl choline was not inhibited. Under these conditions, appearance of labelled protein in myelin was inhibited by 90 per cent, while the appearance of newly labelled sulphatide and phosphatidyl choline in myelin membrane was not greatly affected. Experiments with cycloheximide gave similar results with phosphatidyl choline, but incorporation of ³⁵S]sulphate into total sulphatide was decreased by about 30 per cent in animals given cycloheximide. Neither puromycin nor cycloheximide had any inhibitory effect on galactocerebroside sulphotransferase.