金腰带治疗对大鼠损伤脊髓BDNF、NMDA受体表达及行为学的影响

目的研究中草药金腰带治疗对脊髓损伤(SCI)大鼠行为学、脑源性神经营养因子(BDNF)表达及N-甲基-D-门冬氨酸(NMDA)受体水平的影响。方法 SD成年雄性大鼠,随机分为假手术组、脊髓挫伤组(SCI组)、脊髓挫伤后金腰带治疗组〔每日1次胃内灌服金腰带50mg/(kg.d),共7次〕。各组大鼠均在术后(0d、3d、10d、28d)进行后肢行为学评价(BBB运动功能评分)。术后13d,每组取8只大鼠麻醉后取损伤脊髓T10液氮中保存,采用3 H]MK-801放射性配基分析法测定NMDA受体亲和力(Kd)和最大结合数量(Bmax);取术后28d组大鼠损伤脊髓进行免疫组织化学染色,观察BDNF在脊髓的定位及表达变化。结果 BBB评分SCI组大鼠各时间点均低于假手术组(P均<0.05),而金腰带治疗组术后各时间点均高于SCI组(P均<0.05)。SCI后13d,脊髓内NMDA受体Bmax较假手术组增高(P<0.05),金腰带组较SCI组减少(P<0.05);SCI后28d损伤处脊髓腹角、背角BDNF阳性神经元数量较假手术组增加(P<0.05),金腰带治疗组BDNF阳性神经元数量较SCI组进一步增加(P<0.05)。结论金腰带治疗能有效改善SCI大鼠后肢运动功能,增加脊髓组织中BDNF的表达和通过影响脊髓NMDA受体减轻脊髓继发性损伤,对SCI有一定的治疗与保护作用。

Effect of gold belt on the BDNF and NMDA receptor expression and behaviour changes in rats following traumatic spinal cord injury

Objective To study the effects of gold belt（GB）, a Chinese Herbal,on behavioral changes and brain derived neutrophic factor（BDNF） expression and N-methyl-D-aspartic acid（NMDA） receptor level in rats subjected to spinal cord injury（SCI）.Methods Adult male SD rats were randomly divided into three groups: ①Sham group;②Spinal cord injury group（SCI group）;③Spinal cord injury followed with gold belt treatment（gold belt 50 mg/（kg·d）,intragastric gavage once daily for 7 days） group（GB group）.The Basso,Beattie and Bresnahan （BBB） locomotor scale method was performed to evaluate the hindlimb motor function in the days 0,3,10 and 28.After 13 days,8 rats in each group were treated with 1% sodium pentobarbital（30 mg/kg）,myoloid tissue in T₁0 position was taken and stored in liquid nitrogen to detect NMDA receptor affinity and maximum binding amount（Bmax） with radioligand binding assay.After 28 days,rats were sacrificed and the spinal cords were harvested for immunohistochemistry to observe the localization of BDNF in the ventral and dorsal horn of the spinal cord.Results After spinal cord contusion,GB resulted in a significant increase on the number of BDNF positive neurons compared with traumatic group,and increased BBB score and decreased NMDA receptor were also found in GB group.Whereas decreased BDNF expression,NMDA receptor affininty（Kd） were observed in traumatic injury group.Conclusion The gold belt treatment could effectively improve motor function,increase expression of BDNF,reduce the level of NMDA receptors in SCI rats.These data suggested that the gold belt played a role in the neuroplasticity after spinal cord injury.