超短波对急性脊髓损伤大鼠神经功能及BDNF-TrkB表达的影响

Effects of ultrashort wave on the recovery of neurological function and the expression of BDNF and TrkB in rats with acute spinal cord injury

目的:观察无热量超短波对急性脊髓损伤大鼠神经功能恢复和BDNF-TrkB表达的影响,并探讨其可能作用机制。方法:成年雌性SD大鼠72只,随机分为Sham组(24只)、SCI组(24只)和USW组(24只)。应用改良Allen法制备大鼠脊髓损伤模型。Sham组仅行椎板切除术暴露硬脊膜,不予打击,直接缝合,术后不给予任何治疗。USW组在脊髓损伤造模后24h给予受损部位无热量超短波治疗(最大输出功率40W,实际输出功率11.58W),10min/次,1次/d,至取材前。SCI组造模后不给予任何治疗。在造模后1d、7d、14d和21d用BBB评分、体感诱发电位(SEPs)和运动诱发电位(MEPs)评定脊髓损伤后后肢功能恢复情况并获取损伤段脊髓标本,术后4周取材,用免疫组织化学方法检测SCI组和USW组脊髓在损伤后不同时段BDNF及TrkB的表达,并行阳性细胞计数。结果:BBB评分结果提示,USW组大鼠7d、14d、21d时的运动功能恢复较SCI组明显提高(P<0.01);SEPs和MEPs结果显示,USW组大鼠7d、14d、21d时的神经功能较SCI组明显改善(P<0.05);免疫组织化学方法提示,与SCI组相比,USW组在一定时间段能上调损伤脊髓区BDNF-TrkB的表达(P<0.05)。结论:无热量超短波能在一定程度上促进损伤脊髓的神经功能恢复,其机制可能与超短波上调损伤区脊髓BDNF-TrkB的表达有关。

Objective： To investigate the effects of athermal ultrashort wave on the recovery of neurological function and the expression of BDNF-TrkB after acute spinal cord injury. Method： Totally 72 adult female SD rats were randomly divided into Sham group （24）, SCI group （24） and USW group （24）. The model of spinal cord injury was created by a modified Allen＇s method. The sham group underwent the laminectomy only with no impact injury of spinal cord. The USW group received a thermal ultrashort wave treatment with power of 11.58 W and treatment duration of 10 minutes, once a day. And the ultrashort wave treatment was carried out at 24 hours after SCI until the rats were sacrificed. The SCI group and the sham group received no ulrtashort wave irradiation after surgery. The Basso, Beattie, and Bresnahan （BBB） scale was used to evaluate the hindlimb motor function at 1, 7, 14 and 21 days after SCI. Somatosensory evoked potentials（SEPs） and motor evoked potentials（MEPs） were also performed to detect the neural conduction at the same time. Immunohistochemistry method was used to examine the expression of BDNF and TrkB. Result： The BBB scores was signi？cantly increased in the USW group compared to the SCI group from 7 days to 21 days （P〈0.01）. The results of SEPs and MEPs showed that the recovery of neurological function in the USW group was improved more obviously compared with the SCI group after 7, 14, 21 d （P〈0.05）. The expression of BDNF-TrkB after 7, 14, 21d was higher in the USW group than those in the SCI group （P〈0.05）, and decreased as time went on. Conclusion： Athermal ultrashort wave could promote the recovery of neurological functional after spinal cord injury, and the mechanism might be related to the increase of BDNF-TrkB expression after using ultrashort wave treatment in spinal cord damage zone.