Serotonin Content of the Lungs, Brains, and Blood of Mice Exposed to 0.45 ppm Nitrogen Dioxide

Abstract

Young adult male Swiss Webster mice were exposed to 0.45 ppm of nitrogen dioxide (NO2) for 7 hours per day for 4 weeks. The lungs and brains were assayed for serotonin (5-HT) and 5-hydroxyindoleacetic acid (5-HIAA) content by high-performance liquid chromatography. Lung 5-HT content for the exposed animals was 13.1% less than that for the control group, but this difference was not statistically significant. Brain 5-HT and 5-HIAA were significantly elevated, +17.3% (P < 0.005) and +47.3% (P 0.001), respectively, and the ratios of 5-HIAA to 5-HT were also higher (P 0.005). The results suggest that further exploration of lung and brain serotonin alterations by air pollutants may offer useful discriminates for the evaluation of air quality.