Hyperbaric oxygenation reduces the cytostatic activity and transcription of nitric oxide synthetase gene of mouse peritoneal macrophages.

The effects of hyperbaric oxygenation (HBO) and hyperbaric air (HBA) on the cytostatic activity, peroxynitrite synthesis and transcription of the inducible nitric oxide synthetase (iNOS) gene of murine peritoneal macrophages were studied in vitro. Exposure of mice to HBO or HBA significantly reduced the cytostatic activity, peroxynitrite synthesis and transcription of iNOS mRNA of their macrophages stimulated with lipopolysaccharide (LPS) and interferon-gamma (IFN-gamma). These results indicate that HBO and HBA treatments of mice reduce the cytostatic activity of peritoneal macrophages by reducing iNOS mRNA synthesis.