title: A mixture of nucleosides and nucleotides increases bone marrow cell and peripheral neutrophil number in mice infected with methicillin-resistant Staphylococcus aureus.
abstract: We studied the effects of a mixture of nucleosides and nucleotides on the peripheral neutrophil number and the proliferation of bone marrow cells in mice challenged with methicillin-resistant Staphylococcus aureus. BALB/c mice were fed a nucleotide-free 20% casein diet (control) or this diet supplemented with nucleosides and nucleotides orally (Expt. 1) or intraperitoneally (Expt. 2 and 3). On d 10, the mice were challenged intravenously with methicillin-resistant S. aureus (6.7 x 10(12) colony forming units/L). In Expt. 1 and 2, numbers of total and differential counts of blood leucocytes were counted on d 0 (before), 1, 3 and 5 after the infection. In Expt. 3, 30 min before killing, bromodeoxyuridine (20 mg/kg), an analogue of thymidine, was administered intraperitoneally and its incorporation in the DNA synthetic phase of bone marrow cells was determined at 0 h (before), 3, 6 and 24 h after the infection. Mice fed the supplemented diet had higher (P < 0.05) leucocyte and neutrophil numbers on d 0 compared with the control group. The neutrophil numbers tended to be greater in the supplemented group at 1, 3 and 5 d after the infection. Intraperitoneal administration of nucleosides and nucleotides increased (P < 0.05) neutrophil numbers before and after the infection. Twenty-four h after the infection, incorporation of bromodeoxyuridine into the DNA synthetic phase of bone marrow cells in the group administered nucleosides and nucleotides was higher (P < 0.05) than in the control group. We conclude that, following methicillin-resistant S. aureus injection, intraperitoneal administration of a nucleoside-nucleotide mixture may stimulate bone marrow cell proliferation and increase the peripheral blood neutrophil numbers. Oral administration may elicit weaker effects.
authors.affiliation: Department of Nutrition, Faculty of Medicine, University of the Ryukyus, Okinawa, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Matsumoto
authors.forename: A A
authors.initials: AA
authors.lastname: Adjei
authors.forename: K
authors.initials: K
authors.lastname: Yamauchi
authors.forename: M
authors.initials: M
authors.lastname: Kise
authors.forename: Y
authors.initials: Y
authors.lastname: Nakasone
authors.forename: Y
authors.initials: Y
authors.lastname: Shinagawa
authors.forename: H
authors.initials: H
authors.lastname: Yokoyama
authors.forename: S
authors.initials: S
authors.lastname: Yamamoto
mesh_terms: D000818:Animals; D001853:Bone Marrow / Q000187:drug effects / Q000378:metabolism; D001854:Bone Marrow Cells; D001973:Bromodeoxyuridine / Q000378:metabolism; D004247:DNA / Q000378:metabolism; D007958:Leukocyte Count; D008712:Methicillin / Q000627:therapeutic use; D016106:Methicillin Resistance / Q000235:genetics; D051379:Mice; D008807:Mice, Inbred BALB C; D009504:Neutrophils / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D009705:Nucleosides / Q000378:metabolism / Q000494:pharmacology*; D009711:Nucleotides / Q000378:metabolism / Q000494:pharmacology*; D011897:Random Allocation; D016196:S Phase; D013047:Specific Pathogen-Free Organisms; D013203:Staphylococcal Infections / Q000188:drug therapy / Q000382:microbiology / Q000473:pathology*; D013211:Staphylococcus aureus / Q000187:drug effects; D013997:Time Factors
chemical_list: D009705:Nucleosides; D009711:Nucleotides; D004247:DNA; D001973:Bromodeoxyuridine; D008712:Methicillin