【摘要】 目的　研究GABAB 受体激动剂baclofen对慢性神经痛大鼠痛阈的影响以及对脊髓c fos表达的影响 ,探讨脊髓GABA能系统在神经痛调节中的可能机制。方法　结扎大鼠左侧L5脊神经根建立慢性神经痛模型。SD大鼠 2 4只随机等分成 (1)假手术 +baclofen组 :大鼠背部假手术而未行神经根结扎 ,术后 2 8至 34d每天腹腔注射baclofen 10mg/kg两次 ;(2 )假手术组 :背部假手术后2 8至 34d每天腹腔注射 0 9%NaCl 2ml两次 ;(3)L5结扎 +baclofen组 :实施L5神经根结扎 ,术后2 8至 34d每天腹腔注射baclofen 10mg/kg两次 ;(4)L5结扎组 :实施L5神经根结扎 ,术后 2 8至 34d每天腹腔注射 0 9%NaCl 2ml两次。术后 1、3、7、10、14、2 1、2 8、35d测大鼠双后肢光热刺激性痛阈。术后 35d处死大鼠取出腰段脊髓 ,冰冻切片 ,免疫组化法检测c fos免疫阳性细胞。结果　 (1)术后 7～ 2 8d ,左L5脊神经结扎大鼠较假手术大鼠痛阈明显降低 (P <0 0 1)。术后 35d ,使用与不使用baclofen大鼠的假手术大鼠左后肢痛阈无显著变化 (P >0 0 5 ) ,双侧脊髓深层 (Ⅲ Ⅹ层 )FLI细胞无显著差异 (P >0 0 5 ) ;(2 )术后 35d ,使用baclofen的L5结扎大鼠的左后肢痛觉显著低于未使用baclofen的L5结扎大鼠 (P <0 0 1) ,前者脊髓深层 (Ⅲ Ⅹ层 )FLI细胞显著?更多还原

【Abstract】 Objective To investigate the effect of baclofen,a kind of GABA B agonist,on c fos expression of the rat spinal cord and hyperalgesia in a model of chronic neuropathic pain Methods Chronic neuropathic model was set up by ligation of left L 5 spinal nerve of rat Twenty four SD rats were randomly divided into four groups with six in each (1)Sham operation+baclofen group:baclofen 10mg/kg was adminstrated(ip) twice a day from the twenty eighth to thirty fourth day after sham operation (2)Sham operation group:0 9% NaCl 2ml was adminstrated(ip) twice a day from the twenty eighth to thirty fourth day after sham operation (3)L 5 ligature+baclofen group:left L 5 spinal nerve of rats was ligated by sild and then treated as the first group (4)In L 5 ligation group,the same operation was performed as that in group 3 and then treated with as group 2 Pain threshold of rat’s two hindlimbs was measured by heat stimulation on the first,third,seventh,tenth,fourteenth,twenty first,twenty eighth,thirty fifth day after operation Lumbar spinal cord of rat was taken out on the thirty fifth day,then frozen section was made C fos like immuno reactivity(FLI) cells were identified by the immunohistochemical technique Results Compared with sham group,pain threshold of rat’s left hindlimb of ligature group measured by heat stimulation was lower from the seventh day to twenty eigth day after operatin( P< 0 01) On the thirty fifth day,pain threshold of rat of group 1 was not different with that of group 2( P> 0 05),and FLI cells in deep layer of lumbar spinal cord of group 1 were not different with that of group 2( P> 0 05) Pain of rat of group 3 was lower than that of group 4( P< 0 01),and FLI cells in deep layer of lumbar spinal cord of group 3 were fewer than that of group 4 on the thirty fifth day ( P< 0 01) Conclusions FLI cells air expressed in the deep layer of spinal cord in a model of chronic neuropathic pain Baclofen may attenuate hyperalgesia in a rat model of chronic neuropathic pain and reduce FLI cells in deep layer of spinal cord after nerve injury更多还原