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. Copyright (C) 1999 Elsevier Science B.V.
- Bacteria, Streptococcus pneumoniae
- Enzymes, xanthine oxidase
- Infection, gastric juice, streptococcus, pneumonia
- Mammals, mouse
ASJC Scopus subject areas
- Pulmonary and Respiratory Medicine