Related Experiment Videos
Superoxide dismutase inhibits brain oedema formation in experimental pneumococcal meningitis
H W Pfister1, U Koedel, U Dirnagl
1Department of Neurology, University of Munich, Federal Republic of Germany.
Abstract:
The purpose of this study was to identify mediators of brain oedema formation in experimental pneumococcal meningitis. In a rat model of pneumococcal meningitis brain water content was significantly elevated 6 hours post infection (79.69% +/- 0.24 compared to 78.94% +/- 0.16 in the control group, mean +/- SEM, p less than 0.05). Brain oedema formation was completely blocked by superoxide dismutase (132,000 U/kg i.v. per 6 hours: n = 6), pretreatment with dexamethasone (3 mg/kg i.p., n = 3), or administration of dexamethasone at two hours after pneumococcal injection (n = 5). Pretreatment with indomethacin (10 mg/kg i.v., n = 5) attenuated the brain oedema formation. These findings suggest that oxygen derived free radicals act as mediators of brain oedema formation during the early phase of experimental bacterial meningitis. Cyclooxygenase metabolites may provide one possible source for the generation of oxygen derived free radicals in bacterial meningitis.
Insights
Free radicals contribute to brain swelling in bacterial meningitis. Treatments like superoxide dismutase and dexamethasone blocked this early-stage brain oedema, suggesting free radicals as key mediators.
Area of Science:
- Neurology
- Infectious Diseases
- Pathophysiology
Background:
- Bacterial meningitis, particularly pneumococcal meningitis, can lead to severe brain oedema.
- Understanding the early mechanisms of brain oedema is crucial for effective treatment.
Purpose of the Study:
- To identify the key mediators responsible for brain oedema formation in experimental pneumococcal meningitis.
- To investigate the role of oxygen-derived free radicals and cyclooxygenase metabolites in early meningitis-induced brain swelling.
Main Methods:
- Utilized a rat model to induce experimental pneumococcal meningitis.
- Measured brain water content to quantify oedema formation at 6 hours post-infection.
- Administered various agents including superoxide dismutase, dexamethasone, and indomethacin to assess their effects on brain oedema.
Main Results:
- Significantly elevated brain water content was observed 6 hours after pneumococcal infection.
- Superoxide dismutase and dexamethasone (administered before or after infection) completely blocked brain oedema.
- Indomethacin pretreatment attenuated oedema formation.
Conclusions:
- Oxygen-derived free radicals are identified as critical mediators of brain oedema during the early phase of experimental bacterial meningitis.
- Cyclooxygenase metabolites may be a significant source of these free radicals, highlighting a potential therapeutic target.