Figure 7.

Effects of l-menthol and the TRPM8 antagonist, AMTB, on respiratory irritation responses elicited by acrolein. Average DB response during exposure to 2.2 ppm acrolein with and without 7 ppm l-menthol. l-Menthol concentration averaged 6.4, 7.6, and 6.8 ppm in the l-menthol, combination and combination+AMTB groups, respectively (P>0.1). AMTB (3 mg/kg, s.c.) did not affect the response in the acrolein or l-menthol groups; therefore, data from nontreated and treated-animals were pooled for these groups. l-Menthol significantly attenuated the response to acrolein, while AMTB significantly diminished the menthol-induced attenuation of the irritant response to acrolein.