Effect of LTC4, a CysLT2 receptor agonist, on αβ-me-ATP induced pain behaviors and Fos expression. (A) Thermal sensitivity was evaluated by measuring withdrawal latency (sec) at pre (pretreatment), 10, 30 and 60 min after intraplantar injection of LTC4 using a plantar test. (B) The nocifensive behaviors induced by αβ-me-ATP (100 nmol) were evaluated by measuring paw-lifting duration (sec). LTC4 was given at several doses of 8 fmol - 80 pmol/paw, and the ensuing hind paw-lifting duration over the following 4 min was measured. #p < 0.05 compared with vehicle treated group. n = 4-6 for each group. (C, D) Fos protein immunoreactivity in the L5 spinal cord induced by αβ-me-ATP (100 nmol) alone (C) and LTC4 (0.8 pmol) followed by αβ-me-ATP intraplantar injection (D). (E) Number of Fos-labeled neurons in spinal laminae I-II shown in C and D. #p < 0.05 compared with vehicle treated group. n = 3 for each group. Scale bar: 100 μm.