Dietary nucleotides reverse malnutrition and starvation-induced immunosuppression
R. P. Pizzini, S. Kumar, A. D. Kulkarni, F. B. Rudolph and C. T. Van Buren
Department of Surgery, University of Texas Medical School, Houston 77030.
The requirement of dietary nucleotide sources for maximal helper T-cell
function has been demonstrated. The effect of dietary nucleotide
restriction was tested during two forms of nutritional stress: starvation
and protein malnutrition. In the starvation model, mice were fed chow diet,
nucleotide free or nucleotide free supplemented with 0.25% yeast RNA, for
at least 4 weeks. The animals were then starved for 5 days, at which time
they were killed and mitogen assays were performed using spleen cells.
Animals previously maintained on the nucleotide-free diet supplemented with
RNA showed a significant increase in spontaneous concanavalin A and
phytohemagglutinin-stimulated blastogenesis. Protein malnutrition was
induced by feeding Balb/c mice a protein-free diet for 7 to 10 days. These
mice then received either the protein-free diet, the nucleotide-free diet,
or the nucleotide-free diet supplemented with 0.25% yeast RNA. Popliteal
lymph node assays were then performed. The chow diet, nucleotide-free diet,
and nucleotide-free diet supplemented with 0.25% yeast RNA led to a
restoration of body weight, but only the chow and supplemented diets
restored significant popliteal lymph node immune reactivity. These studies
using starvation and protein-malnutrition models clearly indicate the
nutritional role of nucleotides in the maintenance and restoration of the
immune response.
