Retention of inhaled 2-methylfuran and 2,5-dimethylfuran.

The respiratory tract retention of 2-methylfuran and 2,5-dimethylfuran in the dog have been studied as part of a broad investigation of substances found in the vapor phase of cigarette smoke. Retention of 2-methylfuran tended to be higher that that of 2,5-dimethylfuran in the upper, lower and total respiratory tract. Uptake of 2-methylfuran ranged from 63-88% in these regions while it was only 53-62% for 2,5-dimethylfuran. Retention of 2,5-dimethylfuran was lower than any of the other compounds studied. However, the majority of either compound will be absorbed by the respiratory tract when inhalation occurs.