Fig. 2.
Effects of tricarbonyldichloro ruthenium (II) dimer (CORM-2), tricarbonylchloro (glycinato)ruthenium (II) (CORM-3), and cobalt protoporphyrin IX (CoPP) on the antiallodynic and antihyperalgesic responses to morphine. Mechanical antiallodynic (A, B), thermal antihyperalgesic (C, D), and thermal antiallodynic (E, F) effects of the subplantar (50 μg; A, C, E) or subcutaneous (1 mg/kg; B, D, F) administration of morphine or vehicle in the ipsilateral paw of sciatic nerve-injured mice pretreated with 10 mg/kg of CORM-2, CORM-3, or CoPP at 10 days after surgery. The effects of the intraperitoneal administration of CORM-2, CORM-3, or CoPP alone are also shown. Data are expressed as mean values of the maximal possible effect (%) for mechanical allodynia and thermal hyperalgesia and as inhibition (%) for thermal allodynia ± SEM (six animals per group). For each behavioral test, * denotes significant differences versus control group treated with vehicle (P < 0.05, one-way ANOVA followed by Student Newman–Keuls test), + denotes significant differences versus control group treated with morphine (P < 0.05, one-way ANOVA followed by the Student Newman–Keuls test) and # denotes significant differences versus group treated with CORM-2, CORM-3, or CoPP plus vehicle (P < 0.05; one-way ANOVA followed by the Student Newman–Keuls test).