Effect of 1 h pre-treatment with TRPV1 antagonists (capsazepine (10 mg/kg, i.p. or 10 μg/site, i.t.) and SB-366791(1 mg/kg, i.p. or 30 μg/site, i.t.)) or vehicle (filled dotted bars) on the increased lumbar spinal cord B
R mRNA level induced by capsaicin (15 mg/kg, s.c.). Data represent the means ± S.E.M. of 4 rats per group. Comparison with capsaicin pre-treated with the vehicle is indicated by + P < 0.01.