Triethyllead-restrained myelin deposition and protein synthesis in the developing rat forebrain

20-day-old rats were acutely intoxicated with triethyllead (PbEt₃). The forebrains of the poisoned and control animals were analyzed on postpartum days 27 or 34, or both. Two myelin subfractions, namely membrane- and myelin-fraction, were isolated. In the forebrains of PbEt₃-treated rats, the deposition of the membrane-fraction was hampered to a greater extent than the deposition of the myelin-fraction. The intoxication caused a significant reduction in the concentration of sulphatides in the myelin-fraction. How-ever, in spite of sulphatides, the intoxication did not influence the protein or lipid content of either subfraction. A close correlation between the degree of inhibition of myelin deposition and of synthesis of myelin proteins was demonstrated in the forebrains of PbEt₃-intoxicated rats. On the other hand, the synthesis of total forebrain protein was less depressed than the synthesis of myelin or its proteins, suggesting greater vulnerability of the myelin-forming cells than other cells in the brain tissue toward PbEt₃-induced intoxication.