title: Double-balloon jejunal perfusion to compare absorption of vitamin E and vitamin E acetate in healthy volunteers under maldigestion conditions.
abstract: OBJECTIVE
  The vitamin E derivative, α-tocopheryl acetate, is often included in formulations used in enteral nutrition. In this respect, we compared α-tocopherol and α-tocopheryl acetate absorption under 'maldigestion' conditions, such as occurring during enteral tube feeding, using differentially labeled RRR-[5,7-methyl-((2)H(6))]-α-tocopherol and RRR-[5-methyl-(2)H(3)]-α-tocopheryl acetate allowing direct comparison between free and esterified forms.
  
  
  METHODS
  The two derivatives were given together in a single dose to six volunteers directly into the jejunum using a double-balloon perfusion system. Perfusion lasted for 1 h, and the collected blood and effluent samples were analyzed by liquid chromatography-mass spectrometry.
  
  
  RESULTS
  In the isolated 20-cm length of exposed jejunum, on average ~ 6% of the two vitamin E forms were absorbed >1 h based on subtraction of effluent from influent. There was substantial difference in the absolute absorbed quantity between individuals, but no significant differences were observed in the absorption between the two labeled forms as assessed in the plasma. (2)H(3)-α-tocopherol was not present in the influent, but appeared in the effluent, indicating that the acetylated form of vitamin E is cleaved by brush border enzymes in the small intestine.
  
  
  CONCLUSIONS
  This study shows that even in the absence of digestive enzymes and bile salts, the appropriately solubilized acetylated form of α-tocopherol exhibits the same bioavailability as free α-tocopherol. This suggests that both forms can be absorbed equally under maldigestion conditions such as present clinically during enteral tube feeding.
authors.affiliation: Nestlé Research Center, Nestec Ltd, Lausanne, Switzerland.
authors.forename: K
authors.initials: K
authors.lastname: Nagy
authors.forename: L
authors.initials: L
authors.lastname: Ramos
authors.forename: M-C
authors.initials: MC
authors.lastname: Courtet-Compondu
authors.forename: S
authors.initials: S
authors.lastname: Braga-Lagache
authors.forename: K
authors.initials: K
authors.lastname: Redeuil
authors.forename: B
authors.initials: B
authors.lastname: Lobo
authors.forename: F
authors.initials: F
authors.lastname: Azpiroz
authors.forename: J-R
authors.initials: JR
authors.lastname: Malagelada
authors.forename: M
authors.initials: M
authors.lastname: Beaumont
authors.forename: J
authors.initials: J
authors.lastname: Moulin
authors.forename: S
authors.initials: S
authors.lastname: Acquistapache
authors.forename: L
authors.initials: L
authors.lastname: Sagalowicz
authors.forename: M
authors.initials: M
authors.lastname: Kussmann
authors.forename: J
authors.initials: J
authors.lastname: Santos
authors.forename: B
authors.initials: B
authors.lastname: Holst
authors.forename: G
authors.initials: G
authors.lastname: Williamson
mesh_terms: D000085:Acetates / Q000378:metabolism / Q000493:pharmacokinetics; D000107:Acetylation; D000328:Adult; D004415:Dyspepsia / Q000378:metabolism*; D004951:Esterification; D006801:Humans; D007408:Intestinal Absorption; D007583:Jejunum / Q000201:enzymology / Q000378:metabolism*; D008297:Male; D012016:Reference Values; D014810:Vitamin E / Q000031:analogs & derivatives / Q000378:metabolism / Q000493:pharmacokinetics*; D024502:alpha-Tocopherol / Q000031:analogs & derivatives / Q000378:metabolism / Q000493:pharmacokinetics
chemical_list: D000085:Acetates; D014810:Vitamin E; D024502:alpha-Tocopherol