Figure 5.

Ablation of isocyanate- and tear gas agent-induced nocifensive responses in mice by genetic deletion or pharmacological blockade of TRPA1. A) Nocifensive responses after application of 10 μl of 100 mM HDI (n=6), 100 mM CS (n=6), or 100 mM CN (n=9) to the eye of untreated C57/BL6 wild-type mice (black bars) and the same mice after an injection of 1 mg i.p.(50 mg/kg, gray bar) or 6 mg i.p.(300 mg/kg, white bar) of TRPA1 antagonist HC-030031. Nocifensive responses were quantified by counting strokes of the orbitofacial area on the observation chamber floor over 2 min for CS and CN for 300 mg/kg experiments and over 3 min for other treatments. Significance: **P < 0.01; *P < 0.05. B) Nocifensive responses (licks, lifts, and flicks) over 3 min after 25-μl subplantar injections of 4 mM CN or 6 mM HDI (n=6/group) into hindpaws of untreated C57/BL6 wild-type mice (black bars) and the same mice after an injection of 2 mg i.p.(100 mg/kg, gray bars). Significance: **P < 0.01; *P < 0.05. C) Comparison of nocifensive responses of wild-type (black bars) and Trpa1^−/− mice (white bars) after application of 10 μl of 200 mM HDI, 100 mM CS, or 100 mM CN to right eye. Strokes of the orbitofacial area against the observation chamber floor were counted over 2 min for CS and CN and for 3 min for HDI (n=6 wild-type and n=6 Trpa1^−/− mice were tested with CN, n=6 wild-type and n=7 Trpa1^−/− mice tested with CS, and n=6 wild-type and n=7 Trpa1^−/− mice were tested with HDI). ***P < 0.001; **P < 0.01; *P < 0.05. D) Nocifensive responses (licks, lifts, and flicks) over 5 min after 25-μl subplantar injections of 2 mM CN (n=8/group) or 4 mM bromoacetone (Br acetone, n=6/group) into hindpaws of Trpa1^+/+ and Trpa1^−/− mice. *P < 0.05.