Studies were designed to explore the role of vitamin E nutritional status in regulating the synthesis of alpha-tocopherol transfer protein (alphaTTP) in rat liver. In vitamin E-replete rats, expression of this protein and its specific messenger RNA (mRNA) was decreased by about 300% compared with rats with normal vitamin E levels. In vitamin E-depleted rats, the alphaTTP-specific mRNA level increased to about 150% of that in the normal vitamin E group. However, protein expression remained constant. These findings indicate that the synthesis of alphaTTP can be regulated by the vitamin E nutritional status.