Alterations in plasma alpha- and gamma-tocopherol concentrations in response to intravenous infusion of lipid emulsions in humans.
To study the fate of intravenously infused vitamin E, we infused lipid emulsions rich in gamma-tocopherol (Intralipid, Kabi, Stockholm, Sweden), or in both alpha- and gamma-tocopherols (Lipidem, Hausmann Laboratories, St Gallen, Switzerland); in normal human volunteers. Plasma gamma-tocopherol levels increased in four subjects infused with Intralipid 10% (0.3 g triglyceride [TG]/kg/h for 6 hours) from 3 +/- 1 to 25 +/- 2 nmol/mL, but by 24 hours they decreased to 5 +/- 1 nmol/mL. Although eight times more gamma-tocopherol was infused, plasma alpha-tocopherol levels also increased from 26 +/- 7 to 39 +/- 9 nmol/mL at 8 hours and decreased to 24 +/- 5 nmol/mL at 24 hours. Increases of alpha-tocopherol in the very-low-density lipoprotein (VLDL) density range occurred at 6 and 8 hours, while decreases occurred in low-density lipoprotein (LDL) and high-density lipoprotein (HDL) density ranges at 3, 6, 8, and 24 hours. Infusion of both emulsions in random order to six subjects at therapeutic rates (0.1 g/kg/h for 6 hours) resulted in (1) a threefold increase in plasma gamma-tocopherol concentrations at 6 hours, (2) increases in plasma alpha-tocopherol concentrations only with Lipidem (from 14.3 +/- 1.0 nmol/mL at 0 hours to 18.4 +/- 2.7 at 6 hours and 18.9 +/- 1.1 at 24 hours), and (3) no decreases in lipoprotein alpha-tocopherol levels.(ABSTRACT TRUNCATED AT 250 WORDS)
Traber
M G
MG
Department of Medicine, New York University School of Medicine, New York 10016.
Carpentier
Y A
YA
Kayden
H J
HJ
Richelle
M
M
Galeano
N F
NF
Deckelbaum
R J
RJ
D000704:Analysis of Variance; D005217:Fat Emulsions, Intravenous / Q000493:pharmacokinetics*; D006801:Humans; D066298:In Vitro Techniques; D008074:Lipoproteins / Q000097:blood; D013997:Time Factors; D014810:Vitamin E / Q000008:administration & dosage / Q000097:blood*
D005217:Fat Emulsions, Intravenous; D008074:Lipoproteins; D014810:Vitamin E