Effect of ATK on CEC-decreased threshold of pain. Pain threshold in animals was measured with AM (A) and DPA (B) for 5 days following CEC. Baseline represents the pain threshold of rats before CEC. CEC + VEH group was hyperalgesic when compared to respective ATK-treated group at least for 3 days following CEC. ATK treatment significantly decreased the hyperalgesia associated with CEC. Data are presented as mean ± SD (n = 8). **p < 0.01, ***p < 0.001 vs. CEC + VEH.