L-arginine-enriched parenteral nutrition affects lymphocyte phenotypes of gut-associated lymphoid tissue.
BACKGROUND
Experimentally, total parenteral nutrition (TPN) diminishes gut-associated lymphoid tissue (GALT) cell numbers and function. Although glutamine supplementation is known to reverse TPN-induced changes in GALT, effects of another conditionally essential amino acid, L-arginine (ARG), on GALT remain unclear.


METHODS
Twenty-two male Institute of Cancer Research mice were randomized to standard TPN (0.3% arginine, STD-total parenteral nutrition) or 1% ARG-enriched TPN (ARG-total parenteral nutrition). After 5 days of feeding, lymphocytes were harvested from Peyer's patches (PP), the lamina propria, and intraepithelial (IE) spaces of the small intestine to determine cell yields. Lymphocyte phenotypes (alphabetaTCR, gammadeltaTCR, CD4, CD8, and B220 as a B cell marker) were determined using flow cytometry. IgA levels in washings of the small intestine, upper respiratory tract, and lungs were measured with ELISA.


RESULTS
ARG-total parenteral nutrition did not affect lymphocyte yields. The percentages of CD4+ cells in PP and IE, and alphabetaTCR+ cells in PP, were significantly higher in the ARG-total parenteral nutrition than in the STD-total parenteral nutrition mice, without marked differences in other phenotypes examined. There were no significant differences in intestinal and respiratory tract IgA levels between the 2 groups of mice.


CONCLUSIONS
One percent ARG supplementation of TPN does not improve GALT cell number or mucosal IgA level but benefits to increase CD4+ cell percentages in GALT.
Fukatsu
Kazuhiko
K
Division of Basic Traumatology, National Defense Medical College Research Institute, Saitama, Japan. fukatsu@res.ndmc.ac.jp
Ueno
Chikara
C
Maeshima
Yoshinori
Y
Hara
Etsuko
E
Nagayoshi
Hidetoshi
H
Omata
Jiro
J
Mochizuki
Hidetaka
H
Hiraide
Hoshio
H
D000818:Animals; D001120:Arginine / Q000494:pharmacology*; D015496:CD4-Positive T-Lymphocytes / Q000187:drug effects / Q000276:immunology; D005434:Flow Cytometry; D007071:Immunoglobulin A, Secretory / Q000032:analysis; D007421:Intestine, Small / Q000166:cytology / Q000187:drug effects* / Q000276:immunology; D018655:Lymphocyte Count; D008214:Lymphocytes / Q000145:classification*; D008221:Lymphoid Tissue / Q000166:cytology / Q000187:drug effects* / Q000276:immunology; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D010289:Parenteral Nutrition, Total; D010581:Peyer's Patches / Q000187:drug effects / Q000276:immunology; D010641:Phenotype; D011897:Random Allocation
D007071:Immunoglobulin A, Secretory; D001120:Arginine