Figure 3

Role of the peripheral nitric oxide synthesized by NOS1 and NOS2 in the antiallodynic effects of morphine. Mechanical (A, C) and thermal (B, D) antiallodynic effects of the subplantar co-administration of morphine (400 nmol) plus vehicle or different doses of NANT (17.0 - 50.9 nmol; A, B) or L-NIL (44.7 - 134.1 nmol; C, D) in the ipsilateral paw of sciatic nerve-injured WT mice at 21 days after surgery. The effects of the subplantar administration of vehicle and the maximal doses of NANT (50.9 nmol) or L-NIL (134.1 nmol) injected alone are also shown. All drugs were administered 20 min before starting behavioral testing. Data are expressed as mean values of the maximal possible effect (%) for mechanical allodynia and as inhibition (%) for thermal allodynia ± SEM (5-6 animals per group). For each behavioral test and selective inhibitor assayed, * P < 0.05 denotes significant differences vs. group treated with morphine plus vehicle (one way ANOVA followed by Student Newman Keuls test) and + P < 0.05 denotes significant differences vs. group treated with vehicle (one way ANOVA followed by the Student Newman Keuls test).