title: Combined effects of both bacteria and gastric juice on pneumonia in mice.
abstract: The effects of a combined inoculation of gastric juice and Streptococcus pneumoniae on the lungs of mice was investigated. Survival rates of mice inoculated with bacteria alone, gastric juice alone, and both bacteria and gastric juice were compared over 18 days. Xanthine oxidase (XO) activities in the lung tissues of mice inoculated with bacteria and gastric juice were measured and injected with a free radical scavenger, pyran-superoxide dismutase (pyran-SOD). A high mortality rate was observed in mice inoculated with both gastric juice and Streptococcus pneumoniae (81%). Mice inoculated with either Streptococcus pneumoniae or gastric juice showed a separate mortality rate of up to 10% during 18 days after inoculation. XO activity in the lung tissue of the mice inoculated with both gastric juice and bacteria was higher than in mice inoculated with either of them separately. The high mortality rate in the group inoculated with both two agents was reduced to 25% by the administration of pyran-SOD. XO activity raised by Streptococcus pneumoniae and gastric juice was significantly reduced by pyran-SOD. Thus, we suggest an important role in the combined effects of gastric juice and bacteria on pneumonia.
authors.affiliation: Department of Geriatric Medicine, Tohoku University School of Medicine, Sendai, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Iwasaki
authors.forename: T
authors.initials: T
authors.lastname: Ohrui
authors.forename: Q
authors.initials: Q
authors.lastname: Wang
authors.forename: K
authors.initials: K
authors.lastname: Sekizawa
authors.forename: T
authors.initials: T
authors.lastname: Akaike
authors.forename: H
authors.initials: H
authors.lastname: Maeda
authors.forename: H
authors.initials: H
authors.lastname: Sasaki
mesh_terms: D000818:Animals; D005750:Gastric Juice; D008168:Lung / Q000378:metabolism / Q000503:physiopathology*; D008297:Male; D051379:Mice; D009504:Neutrophils / Q000187:drug effects / Q000201:enzymology; D009569:Nitric Oxide / Q000378:metabolism; D011008:Pneumococcal Infections / Q000378:metabolism / Q000382:microbiology* / Q000503:physiopathology*; D013482:Superoxide Dismutase / Q000494:pharmacology; D013481:Superoxides / Q000378:metabolism; D015996:Survival Rate; D014969:Xanthine Oxidase / Q000378:metabolism
chemical_list: D013481:Superoxides; D009569:Nitric Oxide; D013482:Superoxide Dismutase; D014969:Xanthine Oxidase