Secretion of alpha-tocopherol in VLDL is decreased by dietary protein insufficiency in young growing rats.
The concentrations of alpha-tocopherol in plasma and most peripheral tissues were shown previously to be low in young growing rats fed a low protein diet. To examine the secretion rates of VLDL alpha-tocopherol and triglycerides, and lipoprotein lipase activity, weanling rats were fed a low protein (LP, 8 g/100 g lactalbumin) or a normal protein (NP, 20 g/100 g lactalbumin) diet for 6 wk. The absolute secretion rate of VLDL triglyceride (micromol/h) of the LP group was not significantly different from that of the NP group (P: > 0.05), but was significantly higher (P: < 0.05) when expressed relative to body weight [micromol/(h. kg)]. The secretion rates of VLDL alpha-tocopherol were significantly lower (P: < 0.05) in the LP group than in the NP group. The activities of hepatic lipase, lipoprotein lipase and total heparin-releasable lipase in plasma of the LP group were only 50-60% those of the NP group (P: < 0.05). The results demonstrated that the secretion rate of VLDL alpha-tocopherol and activities of lipases in postheparin plasma were significantly lower in rats fed a low protein diet. Thus, the redistribution of alpha-tocopherol from liver to peripheral tissues appears to have been impaired by dietary protein insufficiency.
Shaw
H M
HM
Laboratory of Nutritional Biochemistry, Department of Agricultural Chemistry, National Taiwan University, Taipei, Taiwan 106.
Huang
C J
CJ
D000818:Animals; D018753:Diet, Protein-Restricted; D004044:Dietary Proteins / Q000008:administration & dosage* / Q000378:metabolism; D008071:Lipoprotein Lipase / Q000378:metabolism; D008079:Lipoproteins, VLDL / Q000097:blood / Q000378:metabolism*; D008099:Liver / Q000201:enzymology / Q000378:metabolism; D008297:Male; D011488:Protein Deficiency / Q000378:metabolism*; D011506:Proteins / Q000378:metabolism; D051381:Rats; D020318:Rats, Long-Evans; D013997:Time Factors; D014280:Triglycerides / Q000097:blood / Q000378:metabolism*; D014810:Vitamin E / Q000097:blood / Q000378:metabolism*
D004044:Dietary Proteins; D008079:Lipoproteins, VLDL; D011506:Proteins; D014280:Triglycerides; D014810:Vitamin E; D008071:Lipoprotein Lipase