Figure 7.

Ability of BU10119 (1 mg·kg⁻¹), the combination of buprenorphine/naltrexone (both at 1 mg·kg⁻¹, BUP/NTX) and the κ antagonist norBNI to block stress‐induced effects. Drug treatments were administered 1 h prior to acute restraint stress (1 × 2 h, Day 1) and daily repeated restraint stress (3 × 2 h, Day 3) in adult male CD1 mice. (A) Stress‐induced analgesia was evident, in the warm‐water tail‐withdrawal assay, as increased %MPE. Test latencies were assessed immediately following the restraint session. *P < 0.05 compared to all groups within the same day. (B) Blood samples were taken at baseline and immediately following the last session of restraint to assess plasma corticosterone. All blood samples were taken during the light phase 11:00–13:00 h. *P < 0.05, compared to non‐stress saline post day 3; #P < 0.05, compared to baseline for the same treated group. All values are the mean ± SEM (n = 6 per group, separate experimental groups in A and B).