抄録
The dynamic pathway of inhaled nitrogen dioxide was investigated in rats exposed to 15NO2 for the specified experimental period. After exposure, various organs, blood and urine were taken out, dried by lyophilization, and then digested by the semi-micro Kjeldahl method. Determination of 15N was performed by mass-spectrometry. The 15N content (atom % excess) of each sample was calculated by subtracting the natural 15N content which was separately estimated from normal rats. The 15N content was relatively high in urine, plasma and kidneys, and low in liver, trachea, heart and brain. It was concluded that the inhaled nitrogen dioxide was quickly absorbed into blood and was excreted into urine. Nitrite was detected in the plasma obtained from the rats exposed to 15NO2 at levels higher than 10 ppm, and a significant correlation was found between the concentration of nitrite and the exposure concentration of 15NO2.
