Figure 10.

(a) Concentration of NO₂^-/NO₃^- (μM) in BALF of rats 2 weeks after intratracheal instillation of silica or saline and intraperitoneal injection of saline or ω-nitro-L-arginine methyl ester (L-NAME) (mean + se). ** There is a statistically significant difference in comparison with control groups. * There is a statistically significant difference in comparison with instillation of silica and injection of saline group. (b) Concentration of NO₂^-/NO₃^- (μM) in BALF of rats 4 weeks after intratracheal instillation of silica or saline and intraperitoneal injection of saline or ω-nitro-L-arginine methyl ester (L-NAME) (mean + se). ** There is a statistically significant difference in comparison with control group. * There is a statistically significant difference in comparison with instillation of silica and injection of saline group.