Abstract: Objective To explore the effects of intrathecal injection of sigma-1 receptor antagonist BD1047 for neuropathic pain(NP) rats pain threshold and activation of spinal microglia. Methods The left common sciatic nerve of anesthetized rats was tied loosely to establish the chronic constriction injury(CCI) model. ① Twenty-four Sprague-Dawley(SD) male rats were randomized into three groups(n=8): sham group(group S), CCIgroup(group C) and CCI+BD1047 group (group B). Saline(20 μl) or BD1047(120 nmol/20 μl) were given intrathecally once a day for 6 days starting from day 0 after operation. Paw withdrawal mechanical threshold(PWMT) was measured one day before operation and on day 3,5,7,10,14 after operation. ② Twelve SD male rats were randomized into three groups(n=4), the grouping and handling method are the same as Part one. Rats were killed on day 10 after operation and the L4-L6 spinal cord segments were removed to measure the expression of microglial by immunofluorescence techniques. Results Compared with group S, PWMT[(4.9±0.9) g]were significantly decreased since the third day after operation and microglial cells(149±28) were significantly increased on day 10 after operation in group C(P<0.05). Compared with group C, PWMT[(8.6±1.2) g]were significantly increased since the third day after operation and microglial cells (92±22) were significantly decreased on day 10 after operation in group B(P<0.05). Conclusions Intrathecal treatment of BD1047 relieves mechanical allodynia by inhibiting the activation of spinal microglial cells of NP rats.
|