Mucosal immunity preservation with bombesin or glutamine is not dependent on mucosal addressin cell adhesion molecule-1 expression.
BACKGROUND
Mucosal addressin cell adhesion molecule-1 (MAdCAM-1) is an adhesion molecule that directs naive T and B cells into Peyer's patches for sensitization and distribution to intestinal and extraintestinal sites. With no enteral stimulation, its expression drops rapidly in association with reduced Peyer's patch cell populations and increases rapidly with reinstitution of enteral feeding. Because both glutamine (GLN) and bombesin (BBS) preserve mucosal immunity, this study examined whether they preserve MAdCAM-1 expression.


METHODS
In 2 separate experiments, animals were randomized to IV cannulation with chow, total parenteral nutrition (TPN), and (experiment 1) 15 microg/kg BBS 3 times per day or (experiment 2) an isocaloric, isonitrogenous 2% GLN-supplemented solution. After 5 days of feeding, MAdCAM-1 expression in Peyer's patches, spleen, and intestine was measured using a dual radiolabeled monoclonal antibody technique.


RESULTS
MAdCAM-1 expression was not significantly improved from TPN levels either with BBS or GLN supplementation. Levels of MAdCAM-1 expression remained unchanged in non-Peyer's patch sites.


CONCLUSIONS
Although MAdCAM-1 is considered the gateway molecule for cell entry into mucosal immunity, this does not seem to be the mechanism for mucosal immunity preservation in nonenterally fed mice receiving bombesin or glutamine.
Zarzaur
Ben L
BL
Department of Surgery, University of Wisconsin, Madison 53792-7375, USA.
Ikeda
Shigeo
S
Johnson
Cheryl D
CD
Le
Tho
T
Sacks
Gordon
G
Kudsk
Kenneth A
KA
D000818:Animals; D001839:Bombesin / Q000494:pharmacology*; D015815:Cell Adhesion Molecules; D005973:Glutamine / Q000494:pharmacology*; D018928:Immunity, Mucosal / Q000187:drug effects*; D007136:Immunoglobulins / Q000187:drug effects / Q000378:metabolism*; D007421:Intestine, Small / Q000187:drug effects / Q000276:immunology / Q000378:metabolism; D008198:Lymph Nodes / Q000187:drug effects / Q000276:immunology / Q000378:metabolism; D008297:Male; D008643:Mesentery; D051379:Mice; D008813:Mice, Inbred ICR; D009088:Mucoproteins / Q000187:drug effects / Q000378:metabolism*; D010289:Parenteral Nutrition, Total / Q000009:adverse effects; D010581:Peyer's Patches / Q000187:drug effects / Q000276:immunology / Q000378:metabolism; D011897:Random Allocation; D013154:Spleen / Q000187:drug effects / Q000276:immunology / Q000378:metabolism
D015815:Cell Adhesion Molecules; D007136:Immunoglobulins; C489082:Madcam1 protein, mouse; D009088:Mucoproteins; D005973:Glutamine; D001839:Bombesin