Glutamine-enriched total parenteral nutrition maintains intestinal interleukin-4 and mucosal immunoglobulin A levels.
BACKGROUND
Total parenteral nutrition (TPN) prevents progressive malnutrition but fails to maintain intestinal gut-associated lymphoid tissue (GALT) or established respiratory antiviral or antibacterial mucosal immunity. Our previous work demonstrated that decreases in intestinal immunoglobulin A (IgA) were associated with decreases in Th2-type IgA-stimulating cytokines, interleukin (IL)-4 and IL-10. Because glutamine supplementation of TPN partially preserves respiratory defenses and normalizes GALT, we investigated the ability of parenteral glutamine to normalize respiratory and intestinal IgA levels and measured Th2 cytokines in intestinal homogenates.


METHODS
Animals were cannulated and randomly assigned to receive chow (n = 17), TPN (n = 18), or an isonitrogenous, isocaloric TPN solution formulated by removing the appropriate amount of amino acids and replacing them with 2% glutamine (n = 18) for 5 days. Respiratory tract and intestinal washings were obtained for IgA and the intestine homogenized and analyzed for IL-4 and IL-10.


RESULTS
TPN decreased intestinal and respiratory IgA in association with decreases in intestinal IL-4 and IL-10 compared with chow-fed animals. Glutamine significantly improved respiratory and intestinal IgA levels, significantly improved IL-4 compared with TPN animals, and maintained IL-10 levels midway between chow-fed and TPN animals.


CONCLUSIONS
Glutamine-enriched TPN preserved both extraintestinal and intestinal IgA levels and had a normalizing effect on Th2-type IgA-stimulating cytokines.
Kudsk
K A
KA
University of Tennessee, Memphis, USA.
Wu
Y
Y
Fukatsu
K
K
Zarzaur
B L
BL
Johnson
C D
CD
Wang
R
R
Hanna
M K
MK
D000818:Animals; D005973:Glutamine / Q000008:administration & dosage / Q000494:pharmacology*; D007070:Immunoglobulin A / Q000032:analysis / Q000187:drug effects*; D016753:Interleukin-10 / Q000032:analysis; D015847:Interleukin-4 / Q000032:analysis*; D007413:Intestinal Mucosa / Q000276:immunology*; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D010289:Parenteral Nutrition, Total; D011897:Random Allocation; D012137:Respiratory System / Q000276:immunology*
D007070:Immunoglobulin A; D005973:Glutamine; D016753:Interleukin-10; D015847:Interleukin-4