Fig. 7.

Blocking CCI-caused increase in OCT1 in the injured DRG improves MOR-mediated analgesia under CCI-caused neuropathic pain conditions. (A) Effect of pre-microinjection of OCT1 siRNA or vehicle (Veh) into the unilateral L4/5 DRG on morphine analgesia on the ipsilateral and contralateral sides 3 days after CCI or sham surgery. n = 5 rats/group. Two-way ANOVA followed by post hoc Tukey test. **P < 0.01 versus the correspondung vehicle plus sham group. #P < 0.05 versus the correspondung vehicle plus CCI group. (B and C) Effect of intraperitoneal injection of methylnatrexone (M) on the OCT1 siRNA-produced antinociceptive effect 4 days post-CCI or sham surgery on the ipsilateral side. n = 5 rats/group. Two-way ANOVA followed by post hoc Tukey test. **P < 0.01 versus the vehicle plus sham group at the corresponding time point. #P < 0.05 versus the vehicle plus CCI group at the corresponding time point.