Absorption of enterally administered N-acetyl-l-glutamine versus glutamine in pigs.
OBJECTIVE
Glutamine instability in liquid media suggests that evaluation of reasonable enteral nutrition sources of glutamine is needed. N-acetyl-l-glutamine offers no instability and no intolerance problems. This research was conducted to study the absorption and apparent digestibility of glutamine versus N-acetyl-l-glutamine.


METHODS
Two pig models were used. (1) In a clamped jejunal loop experiment, we measured the concentrations of glutamine and N-acetyl-l-glutamine in the intestinal infused solutions, intestinal mucosa, and portal and peripheral blood. (2) In a feeding experiment, we determined their apparent digestibility.


RESULTS
N-acetyl-l-glutamine ( approximately 76%) was slightly less absorbed than glutamine ( approximately 85%) from the intestinal lumen into mucosa, where it was not detected as intact molecule, suggesting almost complete hydrolysis during absorption. Virtually no intact N-acetyl-l-glutamine was observed in the blood compartments; glutamine from lumenal N-acetyl-l-glutamine had the same behavior as that from lumenal-free glutamine in portal and peripheral blood. The apparent ileal digestibility of N-acetyl-l-glutamine was lower than that of free glutamine, as N-acetyl-l-glutamine was probably retained in the intestinal lumen to a greater extent than glutamine.


CONCLUSIONS
N-acetyl-l-glutamine appeared to be a good candidate for glutamine fortification of enteral nutrition formulas.
Arnaud
Alexandra
A
Abbott Laboratories, Ross Products Division, International R and D Department, Camino de Purchil 68, Granada 18004, Spain.
Ramírez
Maria
M
Baxter
J H Jeffrey H
JH
Angulo
A J Antonio J
AJ
D000818:Animals; D001682:Biological Availability; D004063:Digestion; D004195:Disease Models, Animal; D004750:Enteral Nutrition; D005947:Glucose / Q000378:metabolism / Q000493:pharmacokinetics; D005973:Glutamine / Q000031:analogs & derivatives* / Q000493:pharmacokinetics*; D007082:Ileum / Q000378:metabolism; D007408:Intestinal Absorption / Q000187:drug effects*; D007413:Intestinal Mucosa; D007583:Jejunum / Q000378:metabolism; D013552:Swine
C032007:aceglutamide; D005973:Glutamine; D005947:Glucose