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 alpha-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 for 4 wk were injected with Triton WR1339 and administered by oral gavage an emulsion containing 10 mg of alpha-tocopherol, 10 mg of gamma-tocopherol, or 29.5 mg of a tocotrienol mixture with 200 mg of sodium taurocholate, 200 mg of triolein, and 50 mg of albumin. alpha-Tocopherol was detected in the serum and other tissues of the vitamin E-deficient rats, but gamma-tocopherol, alpha- and gamma-tocotrienol were not detected. Triton WR1339 injection elevated (P<0.05) the serum alpha-tocopherol concentration and inhibited (P<0.05) the elevation of alpha-tocopherol concentration in the liver, adrenal gland, and spleen due to the oral administration of alpha-tocopherol. Neither alpha-tocopherol administration nor Triton WR1339 injection affected (P>or=0.05) the alpha-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 alpha-tocopherol transfer activity of LPL in adipose tissue and muscle is not important for alpha-tocopherol transport to the tissue after alpha-tocopherol intake or that the amount transferred is small relative to the tissue concentration. Furthermore, Triton WR1339 injection tended to elevate the serum gamma-tocopherol (P=0.071) and alpha-tocotrienol (P=0.053) concentrations and lowered them (P<0.05) in the liver and adrenal gland of rats administered gamma-tocopherol or alpha-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.
Abe
Chisato
C
Department of Nutritional Sciences, Nagoya University of Arts and Sciences, Nissin 470-0196, Japan.
Ikeda
Saiko
S
Uchida
Tomono
T
Yamashita
Kanae
K
Ichikawa
Tomio
T
D000818:Animals; D001692:Biological Transport / Q000187:drug effects; D002839:Chromans / Q000008:administration & dosage / Q000378:metabolism; D008071:Lipoprotein Lipase / Q000037:antagonists & inhibitors* / Q000378:metabolism; D008099:Liver / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D011092:Polyethylene Glycols / Q000008:administration & dosage / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D024508:Tocotrienols; D014280:Triglycerides / Q000008:administration & dosage / Q000097:blood / Q000378:metabolism; D014810:Vitamin E / Q000008:administration & dosage / Q000031:analogs & derivatives / Q000378:metabolism*; D024502:alpha-Tocopherol / Q000097:blood / Q000378:metabolism; D024504:gamma-Tocopherol / Q000097:blood / Q000378:metabolism
D002839:Chromans; D024508:Tocotrienols; D014280:Triglycerides; D014810:Vitamin E; D011092:Polyethylene Glycols; C013649:plastochromanol 8; C082089:tocotrienol, beta; D024504:gamma-Tocopherol; C082032:tocotrienol, alpha; D008071:Lipoprotein Lipase; D024502:alpha-Tocopherol; C016811:tyloxapol