Absence of VLDL secretion does not affect α-tocopherol content in peripheral tissues

• Main Authors: Kaori Minehira-Castelli, Scott W. Leonard, Quinn M. Walker, Maret G. Traber, Stephen G. Young
• Format: Article
• Language: English
• Published: Elsevier 2006-08-01
• Series: Journal of Lipid Research
• Subjects: γ-tocopherol; microsomal triglyceride transfer protein; vitamin E
• Online Access: http://www.sciencedirect.com/science/article/pii/S0022227520331588

α-Tocopherol is a lipid-soluble antioxidant that helps to prevent oxidative damage to cellular lipids. α-Tocopherol is absorbed by the intestine and is taken up and retained by the liver; it is widely presumed that α-tocopherol is then delivered to peripheral tissues by the secretion of VLDL. To determine whether VLDL secretion is truly important for the delivery of α-tocopherol to peripheral tissues, we examined α-tocopherol metabolism in mice that lack microsomal triglyceride transfer protein (Mttp) expression in the liver and therefore cannot secrete VLDL (MttpΔ/Δ mice). MttpΔ/Δ mice have low plasma lipid levels and increased stores of lipids in the liver. Similarly, α-tocopherol levels in the plasma were lower in MttpΔ/Δ mice than in controls, whereas hepatic α-tocopherol stores were higher. However, α-tocopherol levels in the peripheral tissues of MttpΔ/Δ mice were nearly identical to those of control mice, suggesting that VLDL secretion is not critical for the delivery of α-tocopherol to peripheral tissues. When fed a diet containing deuterated α-tocopherol, MttpΔ/Δ and control mice had similar incorporation of deuterated α-tocopherol into plasma and various peripheral tissues. We conclude that the absence of VLDL secretion has little effect on the stores of α-tocopherol in peripheral tissues, at least in the mouse.