RNA


Table of Contents
image The role of dietary sources of nucleotides in immune function: a review
image The biochemistry and physiology of nucleotides
image Dietary nucleotides reverse malnutrition and starvation-induced immunosuppression

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The role of dietary sources of nucleotides in immune function: a review

J Nutr (UNITED STATES) Aug 1994, 124 (8 Suppl) p1442S-1446S

Kulkarni AD; Rudolph FB; Van Buren CT Department of Surgery, University of Texas Medical School at Houston 77030.

Dietary sources of preformed purines and pyrimidines seem to be important for optimal function of the cellular immune response. It was previously assumed that nucleotides were not needed for normal growth and development, but the results described in this review demonstrate a need for nucleotides in the response to immunological challenges. This effect is likely due to a requirement for preformed pyrimidines for proper development and activation of T cells. The need for sources of preformed nucleotides in defined formulas such as parenteral and enteral formulas and infant formulas is suggested by the studies reviewed below. (19 Refs.)



The biochemistry and physiology of nucleotides

J Nutr (UNITED STATES) Jan 1994, 124 (1 Suppl) p124S-127S

Rudolph FB Institute of Biosciences and Bioengineering, Rice University, Houston, TX 77005.

Nucleotides are phosphate esters of nucleosides that contain a sugar linked through a glycosidic linkage with purine and pyrimidine bases. Purine and pyrimidine nucleotides are major components of the cells that make up the monomeric units of DNA and RNA, and they function in all cellular processes. Biosynthesis, inter conversion, catabolism and other aspects of nucleotide metabolism, along with various cellular roles of nucleotides, will be discussed, and the possible use of dietary sources of preformed purines and pyrimidines will be considered. (7 Refs.)



Dietary nucleotides reverse malnutrition and starvation-induced immunosuppression

Pizzini RP; Kumar S; Kulkarni AD; Rudolph FB; Van Buren CT Department of Surgery, University of Texas Medical School, Houston 77030.

Arch Surg (UNITED STATES) Jan 1990, 125 (1) p86-9; discussion 90

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.

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