Figure 3.

Effect of menthol vapor on respiratory irritation by acrolein in metyrapone-treated mice. A) Average DB during exposure to 2.1 ppm acrolein, 16 ppm menthol, and the combination. All mice were pretreated with metyrapone to inhibit nasal CYP450 metabolism. Coexposure with menthol significantly inhibited irritation to levels observed with menthol alone. P values are indicated. B) Time course of DB. DB was increased over baseline throughout acrolein exposure, but only during min 1–2 of exposure in the other groups. As indicated by the asterisks, from min 2 to 15 of exposure, response in the combined group was smaller than in the acrolein group (P<0.05). Data are shown as means ± se; 4–6 mice/group.