Metabolic fate of nitric oxide

The metabolic pathway of inhaled NO in rats was investigated with 15NO. After 15NO exposure, the content of the 15N (atom % excess) in blood, red cells, serum, each organ tissue (perfused with saline solution) and urine were estimated. The contents of 15N in the samples of blood, serum, red cells, and urine were relatively high and those of lung, trachea, liver, kidney, and muscle were low.