Expression of BDNF in dorsal root ganglion of rats with bone cancer pain and its effect on pain behavior

OBJECTIVE To detect the expression of brain-derived neurotrophic factor (BDNF) in dorsal root ganglion (DRG) of rats with bone cancer pain, and to explore the effects of BDNF and anti-BDNF on pain behavior. METHODS 40 SD rats were randomly divided into Sham group and Cancer group (n=20). Rats in Sham were injected with PBS into the tibia, while rats in Cancer group were injected with Walker 256 cells to construct rat tibial bone cancer pain model. Rats in Cancer group were further divided into physiological saline (NS) group and anti-BDNF group (n=10) to observe the effects of anti-BDNF on pain behavior in rats with bone cancer pain. RESULTS Expression level of BDNF and its receptor in DRG of Cancer group was significantly higher than that of Sham group at 3 weeks after inoculation (p⟨0.05). The expression level of BDNF mRNA in the Cancer group was significantly higher than that in the Sham group at 5d, 10d and 20d (p⟨0.05). Hindpaw withdrawal latency was significantly shorter in Cancer group than in Sham group (p⟨0.05). Hindpaw withdrawal mechanical threshold was significantly lower in Cancer group than in Sham group (p⟨0.05). Hindpaw withdrawal latency was significantly longer and hindpaw withdrawal mechanical threshold was significantly higher in anti-BDNF group than in NS group after the use of anti-BDNF (p⟨0.05). CONCLUSION BDNF can aggravate bone pain in rats, and anti-BDNF has obvious antinociceptive function in bone cancer pain.