Effect Of Intrathecal ConG On Excitatory Amino Acid Contents In Spinal Cord In A Rat Model Of Neuropathic Pain

Objective: To observe the relation of chronic constriction injury and the alternation of EAA in the spinal cord, evaluate the effect of NR2B antagon on the expression of EAA in the spinal cord of CCI rats, to evaluate the effect of elective NR2B antagon in neuropathic pain and clinical significance.Method: Thirty male Sprague-Dawley rats were randomly divided into 4 groups: In group I [[(CCI+ ConG) of ConG 0.1 nmol was administered 7 days after operation; In group II (CCI) the rats were placed four loose ligatures around the right sciatic nerve; In group III the animals were shamly operated; In group IV the rats were control group. Rats were tested for hyperalgesia by measuring paw withdrawal latency (PWL) using von-Frey filaments and ice-cold water. The tissue content of excitatory (Glu, Asp) amino acids was determined in the spinal cord. SPSS 11.5 statistical package was used for data analysis. In all cases,ρ<0.05 was considered significant.Results: Asp and Glu contents of the spinal cord were increased significantly in group II as compared with those in group I (ρ<0.05) . Glu contents of the spinal cord in group III and IV (group III 1.24±0.15μmol/g, group IV 1.76±0.35μmol/g)were dramatically lower than that in group I (2.34±0.28μmol/g )and II(2.63±0.19μmol/g) (ρ<0.05). Glu contents of the spinal cord were increased significantly in group II as compared with those in group I,III and IV (ρ<0.05). Asp contents of the spinal cord were increased significantly in group I as compared with those in group II and III. Conclusion: Excitatory amino acid contents in a rat model of neuropathic pain increased in spinal cord. The effect of IT administration ConG may be involved in decline of excitatory amino acid in spinal cord.