Effect of L-menthol on the murine respiratory irritation response to acrolein.

<p>(<i>A</i>) Change in duration of braking (DB) during exposure to 3 ppm acrolein, 40 ppm L-menthol vapor or the combination. Data are presented as the 1 minute average DB level during the baseline (-5 to 0 minute) or the exposure (0 to 15 minute) period, expressed as mean ± SEM (n = 4–7 mice per group). Repeated measures ANOVA followed by Newman-Keuls test indicated the response to the combination was significantly lower than that to acrolein alone (p<0.001). At all exposure times, the response to acrolein+L-menthol was virtually identical to that of L-menthol alone.(<i>B</i>) Effect of 8 or 54 ppm L-menthol on responses to 3, 7 or 11 ppm acrolein. Data are presented as the average DB during the 15 minute exposure (corrected for baseline), expressed as mean ± SEM (n = 5–7 per group). The responses in both the 8 and 54 ppm L-menthol groups were significantly lower than for acrolein alone, and differed significantly from each other (p<0.0001, two-factor ANOVA).