Figure 2.

Effect of menthol vapor on the respiratory irritation response to acrolein. A) Average DB response during 15-min exposure to acrolein (1.9 ppm), menthol (4.1 or 16 ppm), or the combination. Response in the acrolein and acrolein-menthol groups did not differ (P=0.07) at the low menthol concentration; at the high menthol concentration, the response in the acrolein-menthol group was significantly attenuated and not different from the response to menthol alone. P values are indicated. B) Time course of the DB response in the high concentration menthol study. In all groups, DB was increased over baseline during exposure. As indicated by the asterisks, from min 3 to 15 of exposure the response in the combined group was less than in the acrolein group (P<0.05). Data are shown as means ± se; 4–6 mice/group.