Figure 3.

Effects of s.c. injection of DN‐9 and morphine on CCI‐induced neuropathic pain in mice. Time‐response curves for the anti‐allodynic effects induced by 2.37, 4.74, and 9.48 μmol·kg⁻¹ of DN‐9 in male (a) and female (c) mice and 3.11, 9.32, and 31.08 μmol·kg⁻¹ of morphine in male mice (b); anti‐hyperalgesic effects induced by 1.19, 2.37, 4.74, and 9.48 μmol·kg⁻¹ of DN‐9 (d) and 3.11, 9.32, and 31.08 μmol·kg⁻¹ of morphine (e) in male mice and 2.37, 4.74, and 9.48 μmol·kg⁻¹ of DN‐9 in female mice (f). The AUC values of MPE % during the observed period from these data were statistically analysed and presented in the insert. The anti‐allodynic effects induced by 0.095, 0.95, and 9.48 μmol·kg⁻¹ of DN‐9 in male (g) and female mice (h) and 3.11, 6.22, 9.32, and 31.08 μmol·kg⁻¹ of morphine in male mice (g) in an acetone evaporation assay. ^* P < .05, significantly different from saline group; one‐way ANOVA followed by Dunnett's post hoc test. Effects of peripheral administrations of the opioid receptor antagonists naloxone (Nal, 10 mg·kg⁻¹) and naloxone methiodide (NALM, 10 mg·kg⁻¹) and NPFF receptor antagonist RF9 (5 mg·kg⁻¹) on the anti‐allodynic [(i) for mechanical stimuli and (k) for cold stimuli] and anti‐hyperalgesic effects (j) induced by DN‐9. ^* P < .05, significantly different from saline + saline group, ^# P < .05, significantly different from saline + DN‐9 group; one‐way ANOVA followed by Bonferroni's post hoc test, n = 6–10 mice per group