Oral feeding with glutamine prevents lymphocyte and glutathione depletion of Peyer's patches in endotoxemic mice.

OBJECTIVE: To determine the effect of oral glutamine feeding on lymphocyte subpopulations and glutathione metabolism in Peyer's patches (PPs) of healthy and endotoxemic mice. SUMMARY BACKGROUND DATA: Recent data indicate that nutrients both maintain nitrogen and energy balances and modulate cell and organ function. In particular, glutamine has an impact on gut and immune function. This is of special importance in the perioperative phase.
METHODS: Female Balb/c mice were fed a glutamine-enriched diet or a control diet for 10 days. On day 7 25 microg lipopolysaccharide (LPS) or saline was injected. On day 3 after the challenge, mice were killed, total cell yield was determined, and lymphocyte subpopulations (total T cells, CD4+, CD8+ cells, and B cells) were analyzed by flow cytometry. One experimental group was treated with buthionine sulfoximine, a specific inhibitor of glutathione synthesis. The glutathione content in PPs was measured by high-performance liquid chromatography.
RESULTS: Glutamine administration led to a significant increase in total cell yield, including T and B cells, in PPs. The LPS-induced reduction of T cells (-45%) and of B cells (-30%) was significantly lower in glutamine-treated mice. Endotoxemia caused a 42% decrease of glutathione in control animals, but not in glutamine-treated animals. As with LPS, buthionine sulfoximine also lowered lymphocyte numbers and glutathione content of the PPs.
CONCLUSIONS: Administration of glutamine prevents LPS-stimulated lymphocyte atrophy in PPs, possibly by increasing the glutathione content in the PPs. Therefore, oral glutamine supply seems to be a suitable approach for improving intestinal immunity in immunocompromised patients.