Nucleoside-Nucleotide Mixture Increases Bone Marrow Cell Number and Small Intestinal RNA Content in Protein-Deficient Mice After an Acute Bacterial Infection

The aim of this study was to determine if intraperitoneal administration of a nucleoside-nucleotide mixture would affect small intestinal morphology, bone marrow cell number, and DNA content in protein-deficient mice subjected to acute bacterial infection. Mice were randomized into two groups and orally fed protein-free diet or nucleotide-free 20% casein diet for 10 d. The mice in each group were divided into two subgroups and intraperitoneally administered 0.35 mL saline or nucleoside-nucleotide mixture (17.5 mL/kg body weight) for 10 d. On day 10, one subgroup from each major dietary group was either inoculated intravenously with methicillin-resistant Staphylococcus aureus or saline. Three days later, small intestinal morphology, bone marrow cell number, and DNA content were evaluated in infected and noninfected mice. Protein-deficiency in association with infection significantly (P < 0.05) reduced body weight, small intestinal weight, crypt depth, villous height, and wall thickness. All dietary groups exhibited similar small intestinal DNA and protein contents (protein:DNA ratio, RNA:DNA ratio) at 3 d postinfection. However, small intestinal RNA content in the infected protein-free dietary group administered nucleoside-nucleotide mixture was higher (P < 0.05) and tended to be higher relative to the infected nucleotide-free 20% casein group administered nucleoside-nucleotide mixture compared with the rest of the groups. In the infected protein-free dietary group administered nucleoside-nucleotide mixture, bone marrow cell number and bone marrow DNA content were higher (P < 0.05) relative to the infected protein-free dietary group, nucleotide-free 20% casein diet administered saline, or nucleoside-nucleotide mixture, respectively. We conclude that intraperitoneal administration of nucleoside-nucleotide mixture may stimulate bone marrow cell proliferation, DNA content, and small intestinal RNA content during periods of relative deficiency such as protein-deficiency in combination with infection.