Abstract
Diabetic neuropathy pain (DNP), a spontaneous pain with hyperalgesia and allodynia, greatly compromises patients' quality of life. Our previous study suggested that dexmedetomidine (DEX) can relieve hyperalgesia in rats by inhibiting inflammation and apoptosis at the level of the spinal cord. In the present study, we aimed to evaluate the role of Wnt 10a/β-catenin signaling in DEX-induced alleviation of DNP in rats. Forty-eight rats were randomly allocated to four groups (n=12/group): control, DNP, DEX, and yohimbine groups. The DNP model was established by streptozotocin (STZ) injection. The effects of DEX with or without the α 2 adrenergic antagonist yohimbine were assessed by behavior tests (mechanical withdrawal threshold and thermal withdrawal latency). Spinal cord tissue was evaluated by immunofluorescence staining of astrocytes as well as for Wnt 10a and β-catenin expression, western blot analysis of Wnt 10a and β-catenin expression, and enzyme-linked immunosorbent assay measurement of proinflammatory cytokines (tumor necrosis factor-α and interleukin-1β). Rats with STZ-induced DNP had a decreased pain threshold, activated astrocytes, increased expression of Wnt 10a and β-catenin, and increased levels of proinflammatory cytokines compared to the control group, and these effects were ameliorated by treatment with DEX. Yohimbine administration partly abolished the protective effects of DEX in the DNP model rats. In conclusion, DEX alleviated DNP in rats by inhibiting inflammation and astrocyte activation, which may be attributed to downregulation of the Wnt 10a/β-catenin signaling pathway.