[The effect of hyperbaric oxygenation on nitrite and nitrate production in rats treated with endotoxin]

The effect of hyperbaric oxygenation (HBO; 3 ATA, 90 min) on production of stable endproducts of nitric oxide (NO); nitrite (NO2-) and nitrate (NO3-), in plasma was studied in anesthetized rats treated with lipopolysaccharide (LPS). Intravenous injection of LPS (1 mg.kg-1) increased NO2-/NO3- production in plasma significantly 5-6 hrs after treatment, compared with non-treated rats. Production of NO2-/NO3- was not influenced by HBO performed 3 hrs after LPS injection. HBO performed 1 hr after LPS treatment, however, depressed NO2-/NO3- production significantly, compared with HBO performed 3 hrs after LPS, although NO2- production remained increased. These data suggest that HBO may influence the NO2-/NO3- production in NO producing processes in rats treated with LPS.