Figure 3. Lentivirus rescue of IBNtxA analgesia.

(A) Opioid analgesia. Analgesia was determined in groups of mice (n = 6–13) at the stated time. (*P < 0.0001 compared with week 0; ANOVA followed by Tukey). (B) IBNtxA cumulative dose–response curves were carried out in exon 1/exon 11 KO mice with lentivirus vector alone (n = 4), lenti–mMOR-1G (ED₅₀ 1.1 mg/kg [95% CI, 0.72–1.53], n = 18) and WT mice (ED₅₀ 0.42 mg/kg [95% CI, 0.29–0.58], n = 16). (C) Single doses of IBNtxA (2.5 mg/kg, s.c. n = 5), morphine (10 mg/kg, s.c. n = 7), fentanyl (0.08 mg/kg, s.c. n = 7), buprenorphine (1 mg/kg, s.c. n = 7), ketocyclazocine (2 mg/kg, s.c. n = 7), or levorphanol (0.8 mg/kg, s.c. n = 7) were administered to groups of either WT or exon 1/exon 11 KO mice infected with lenti–mMOR-1G. The mice were assessed for analgesia. Another group of mice received IBNtxA with levallorphan (2.5 mg/kg, s.c. n = 7). ANOVA shows that the IBNtxA group and the ketocyclazocine group were significantly different (*P < 0.001 and **P < 0.006 by ANOVA, respectively). The IBNtxA WT and lenti–mMOR-1G animals were not significantly different from each other but were different from both the exon 1/exon 11 KO alone and the lenti–mMOR‑1G/levallorphan groups (Tukey). Ketocyclazocine in WT and lenti–mMOR-1G were not significantly different from each other but were different from exon 1/exon 11 alone (Tukey).