Serum half-life, distribution, hepatic uptake and biliary excretion of alpha-tocopherol in rats.
The serum clearance of alpha-[3H]tocopherol has been studied after intravenous injection of intestinal lymph labeled in vivo with radioactive alpha-tocopherol. The half-life of the injected alpha-[3H]tocopherol was approx. 12 min. Fractionation of plasma by ultracentrifugation 10 min after injection of lymph showed that 91% of the radioactive alpha-tocopherol remaining in plasma was located in chylomicrons (d less than 1.006 g/ml) and 7.8% in high-density lipoproteins (HDL, 1.05 less than d less than 1.21 g/ml). 2 h after administration of alpha-tocopherol, about 35% of the radioactivity recovered in plasma was associated with chylomicrons and approx. 51% with HDLs. alpha-[3H]Tocopherol was initially taken up by the liver, which contained more than 50% of the injected radioactivity after 45-60 min. Separation of parenchymal and nonparenchymal cells demonstrated a preferential uptake of alpha-[3H]tocopherol by the parenchymal liver cells. After 24 h about 11% of the injected dose was recovered in the liver. Considering whole organs the liver, adipose tissue and skeletal muscle had the highest content of radioactivity after 24 h. Furthermore, about 14% of the administered dose was recovered in bile during 24 h draining.
D000273:Adipose Tissue / Q000378:metabolism; D000818:Animals; D001646:Bile / Q000378:metabolism*; D002914:Chylomicrons / Q000097:blood; D006207:Half-Life; D008075:Lipoproteins, HDL / Q000097:blood; D008079:Lipoproteins, VLDL / Q000097:blood; D008099:Liver / Q000378:metabolism*; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D014018:Tissue Distribution; D014810:Vitamin E / Q000097:blood / Q000493:pharmacokinetics*
D002914:Chylomicrons; D008075:Lipoproteins, HDL; D008079:Lipoproteins, VLDL; D014810:Vitamin E