Triton WR1339, an Inhibitor of Lipoprotein Lipase, Decreases Vitamin E Concentration in Some Tissues of Rats by Inhibiting Its Transport to Liver

The aim of this experiment was to clarify the contribution of the α-tocopherol transfer activity of lipoprotein lipase (LPL) to vitamin E transport to tissues in vivo. We studied the effect of Triton WR1339, which prevents the catabolism of triacylglycerol-rich lipoproteins by LPL on vitamin E distribution in rats. Vitamin E-deficient rats fed a vitamin E-free diet for4wk were injected with Triton WR1339 and administered by oral gavage an emulsion containing 10 mg of α -tocopherol, 10 mg of "γ-tocopherol, or 29.5 mg of a tocotrienol mixture with 200 mg of sodium taurocholate, 200 mg of triolein, and 50 mg of albumin. α-Tocopherol was detected in the serum and other tissues of the vitamin E-deficient rats, but γ-tocopherol, α-and γ-tocotrienol were not detected. Triton WR1339 injection elevated (P < 0.05) the serum α-tocopherol concentration and inhibited (P < 0.05) the elevation of α-tocopherol concentration in the liver, adrenal gland, and spleen due to the oral administration of α-tocopherol. Neither α-tocopherol administration nor Triton WR1339 injection affected (P≥0.05) the α-tocopherol concentration in the perirenal adipose tissue, epididymal fat, and soleus muscle despite a high expression of LPL in the adipose tissue and muscle. These data show that α-tocopherol transfer activity of LPL in adipose tissue and muscle is not important for α-tocopherol transport to the tissue after α-tocopherol intake or that the amount transferred is small relative to the tissue concentration. Furthermore, Triton WR1339 injection tended to elevate the serum γ-tocopherol (P= 0.071) and α-tocotrienol (P= 0.053) concentrations and lowered them (P < 0.05) in the liver and adrenal gland of rats administered γ-tocopherol or α-tocotrienol. These data suggest that lipolysis of triacylglycerol-rich chylomicron by LPL is necessary for postprandial vitamin E transport to the liver and subsequent transport to the other tissues.