Figure 1
From: Morphine Induces Hyperalgesia without Involvement of µ-Opioid Receptor or Morphine-3-glucuronide
Design (A) and pharmacodynamic results of study 1 (B, C): effect of saline and NTX pretreatment on morphine- (MOR) or saline-induced changes in TWL in CD-1 mice. (A) Timing of TWL measurements and drug injections. (B) Saline pretreatment caused morphine-induced analgesia. Saline/MOR versus NTX/saline: P < 0.001; *P < 0.001 versus baseline. (C) NTX pretreatment caused morphine-induced hyperalgesia. The combination NTX/saline had no effect on the measured latencies. NTX/MOR versus NTX/saline: P < 0.001; *P < 0.001 versus baseline. Values are means ± SEM.