Figure 4.

(A) Characterization of depolarization (mV) responses elicited by isolated human vagus nerve preparations in response to the TRPA1 agonist acrolein. Results are expressed as means ± SEM of three experiments. (B) A representative trace describing depolarization of isolated human vagus evoked by acrolein (1 mM) and inhibition in the presence of the TRPA1 antagonist AP-18 (10 μM). The response to acrolein is recovered after washout. (C) Concentration–response curve of cinnamaldehyde inhaled at baseline and repeated 1 hour later in human volunteers. Nebulizations were performed with the MEFAR MB3 dosimeter with a Respironics nebulizer chamber and mouthpiece. The dosimeter was set to nebulize for 1 second and 2 ml of the agent was instilled into the nebulizer chamber. Coughs induced were assessed during the subsequent 15 seconds after the nebulization.