The C-terminal heptapeptide of bombesin reduces the deleterious effect of total parenteral nutrition (TPN) on gut-associated lymphoid tissue (GALT) mass but not intestinal immunoglobulin A in vivo.
BACKGROUND
Bombesin, the amphibian analog of mammalian gastrin-releasing peptide, reverses total parenteral nutrition (TPN)-induced atrophy of gut-associated lymphoid tissue and increases intestinal and respiratory immunoglobulin A (IgA) levels. Structure-activity studies suggested that the biologically active portion of bombesin is a C-terminal heptapeptide (7AA). This study investigates the effect of 7AA on lymphocytes counts of the Peyer's patches (PP), the lamina propria (LP) and the intraepithelial layer (IE).


METHODS
Forty-eight male mice were randomized to receive chow (n = 13), TPN only (n = 9), TPN + 15 microg 7AA 3 times per day (n = 13) or TPN + 150 microg 7AA 3 times per day (n = 13). After 5 days of feeding, PP, LP, and IE lymphocytes were determined. Intestinal IgA levels were measured with ELISA. Groups were compared with ANOVA.


RESULTS
All TPN-fed mice lost more weight than mice fed chow (p < .04). Lymphocyte counts in PP, LP, and IE were significantly lower in the TPN group than in the 3 other groups but did not differ between the groups fed chow, TPN + 15 microg 7AA 3 times per day, or TPN + 150 microg 7AA 3 times per day. Intestinal IgA levels were higher in chow-fed mice (148.4 +/- 16.9) than in mice fed TPN (98.4 +/- 14.0, p = .008), TPN + 15 microg 7AA 3 times per day (96.9 +/- 7.7, p = .003) or TPN + 150 microg 7AA 3 times per day (87.3 +/- 6.7, p = .001).


CONCLUSIONS
The C-terminal heptapeptide of bombesin prevented the TPN-induced decrease in intestinal lymphocyte populations but not the reduction in intestinal IgA levels.
Genton
Laurence
L
Department of Surgery, University of Wisconsin Medical School, Madison, Wisconsin 53792-7375, USA.
Reese
Shannon R
SR
Ikeda
Shigeo
S
Le Tho
C
C
Kudsk
Kenneth A
KA
D000704:Analysis of Variance; D000818:Animals; D001839:Bombesin / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004797:Enzyme-Linked Immunosorbent Assay; D007070:Immunoglobulin A / Q000032:analysis*; D007413:Intestinal Mucosa / Q000187:drug effects / Q000276:immunology*; D018655:Lymphocyte Count; D008221:Lymphoid Tissue / Q000187:drug effects / Q000276:immunology*; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D010289:Parenteral Nutrition, Total / Q000009:adverse effects*; D010581:Peyer's Patches / Q000187:drug effects / Q000276:immunology; D011897:Random Allocation; D013329:Structure-Activity Relationship
D007070:Immunoglobulin A; D001839:Bombesin