Fig. 4.
When compared to the vehicle group (V) repeated administration of morphine (tolerant group, T) led to significant increase in dorsal horn tissue levels of 8OHdG (A) and substantially activated PARP (B). These biochemical changes were significantly attenuated by co-administration of morphine over four days with MnTE-2-PyP5+ (3 mg/kg/day, n=12) or MnTnHex-2-PyP5+ (0.1 mg/kg/day, n=12) (A, B). Results are expressed as mean±s.e.m. for twelve animals. *P<0.001 for Morphine alone vs Vehicle; †P<0.001 for Morphine + drug-treated vs Morphine alone.