Yo-Pro uptake was evoked by various TRPA1 agonists and blocked by TRPA1 antagonists. Concentration-effect relationships for agonist responses in the Ca2+ assay (A) and Yo-Pro uptake (B). Reactive agonists: AITC, CA and 4-HNE. Non-reactive agonists: FTS and URB597. Data are represented as percentage of maximal AITC responses. C, representative traces of Yo-Pro uptake in response to a first addition of AP18 (0 to 100 μM) and a second addition of AITC (30 μM). AP18 inhibited AITC evoked Yo-Pro uptake in a concentration-dependent manner. D, concentration-effect relationship of Yo-Pro uptake inhibition by AP18, HC-030031 and RR. (n = 4 – 8).