Nitric oxide synthase activity and nitric oxide level in erythrocytes of guinea pigs with experimental otitis media with effusion.

Free radicals have been implicated in the pathogenesis of an increasing number of disease and inflammatory states. They may cause cell and tissue damage by chemical modification of proteins, carbohydrates, nucleotides and lipids. Under physiological conditions free radicals are parts of normal regulatory circuits and are neutralized by antioxidants. Infections are one cause of increased free radicals production. The aim of our study was to assess whether increased oxidative stress is reflected by erythrocyte nitric oxide synthase activity and nitric oxide levels in guinea pigs with experimental otitis media with effusion (n = 6) and in a control group (n = 6). Erythrocyte nitric oxide synthase activity and nitric oxide levels were measured in both groups. The nitric oxide synthase activity and nitric oxide level in the experimental otitis media with effusion were significantly higher than those of the control group. There was a significant positive correlation between the nitric oxide synthase activity and nitric oxide in the experimental otitis media with effusion group. Thus, increased nitric oxide levels may play an important role in cell and tissue damage due to experimental otitis media with effusion.