Sao Paulo Medical Journal
On-line version ISSN 1806-9460
FRAGOSO, Yara Dadalti and BROWN, Andrew Joseph. In vivo metabolism of alpha-tocopherol in lipoproteins and liver: studies on rabbits in response to acute cholesterol loading. Sao Paulo Med. J. [online]. 1998, vol.116, n.4, pp. 1753-1759. ISSN 1806-9460. http://dx.doi.org/10.1590/S1516-31801998000400003.
OBJECTIVE: To investigate the transport of alpha-tocopherol in lipoproteins of rabbits under normal diet and under acute loading of cholesterol. DESIGN: Two New Zealand White rabbits were fed 14C-alpha-tocopherol acetate in a single oral dose and the recovery of radiolabel in lipoproteins and plasma was monitored. Low density lipoprotein (LDL) from these animals was obtained and labeled with [3H] cholesteryl ester. Three other rabbits were injected with this double-labeled LDL in the native form; while three other animals received this LDL in the acetylated form. RESULTS: Plasma clearance, liver uptake and levels of radiolabel in high density lipoprotein (HDL) of animals injected with 14C[3H]acetyl LDL were significantly higher than those in animals injected with 14C[3H]native LDL. Larger particles of HDL, rich in apolipoprotein E (apoE) carried significantly higher levels of both labels in rabbits injected with acetylated LDL. CONCLUSION: These results provide evidence for in vivo mechanisms of "reverse alpha-tocopherol transport", analogous to "reverse cholesterol transport".
Keywords : Atherosclerosis; Alpha-tocopherol; HDL.