Abstract
In order to study effect of α-tocopherol upon the conversion of β-carotene to vitamin A in the liver, the following experiments were made. Various amounts of aqueous emulsion of α-tocopherol, α-tocopheryl acetate and a definite amount of β-carotene were injected into the femoral vein of a healthy dog, and the determination of serum carotene, vitamin A alcohol and its ester contents of arterial and hepatic venous blood was made, before injection and 5,30,60 and 120 minutes after. A small dose of α-tocopherol stimulated β-carotene uptake in the liver and its conversion to vitamin A in the tissue. A large dose of α-tocopherol stimulated β-carotene uptake in the liver, while it had no effect upon the conversion to vitamin A. A large dose of α-tocopheryl acetate also stimulated β-carotene uptake in the liver, but inhibited the conversion to vitamin A.
