水中平板步行训练对脊髓损伤大鼠运动功能及脑源性神经营养因子、神经营养素-3表达的影响

The effect of underwater partial body-weight-supported treadmill training on hindlimb locomotor function recovery and on the expression of brain-derived neurotrophic factor and neurotrophin-3 in rats after spinal cord injury

目的 探讨水中平板步行训练在脊髓损伤（SCI）大鼠康复中的作用及其与脊髓可塑性的关系.方法 将40只成年雄性Sprague-Dawley大鼠分为假模组、模型对照组、水疗训练组、减重平板训练组及水中平板训练组,每组8只.建立大鼠脊髓挫伤模型,各训练组于术后1周开始进行8周的康复训练.采用BBB评分、爬网格试验评定大鼠后肢功能的恢复,采用免疫组织化学方法检测大鼠脊髓中脑源性神经营养因子（BDNF）、神经营养素-3（NT-3）的表达.结果 水中平板训练组大鼠后肢运动功能较其他组明显改善（P＜0.05）.3个训练组大鼠脊髓前角神经元BDNF及NT-3的表达与模型对照组相比均显著增加（P＜0.05）.BDNF的表达在3个训练组之间两两比较,差异均无统计学意义（P＞0.05）.水中平板训练组NT-3的表达明显高于减重平板训练组（P＜0.05）;而水中平板训练组与水疗训练组相比,差异无统计学意义（P＞0.05）.结论 水中平板训练可能通过影响BDNF及NT-3的表达增强脊髓损伤大鼠脊髓可塑性,促进后肢运动功能的恢复.

Objective To observe the efficacy of underwater partial body-weight-supported treadmill training in repairing spinal cord injury （SCI） and its relationship with spinal nerve plasticity. Methods A total of 40 Sprague-Dawley rats were randomly divided into five groups： a sham model group, a model control group, an underwater training group, a partial body-weight-supported treadmill training （PBWSTT） group and an underwater PBWSTT group. A rat model of SCI was induced by contusion of the T10 segment with a Multicenter Animal Spinal Cord Injury Study （MASCIS） impactor. One week post-operation, different rehabilitation strategies, such as free exercise in water, BWSTT and underwater PBWSTT, were administered to the rats in the underwater training groups for 8 weeks.Those in the sham model group and model control group were given no training. The Basso, Beattie and Bresnahan （BBB） locomotor rating scale and a climbing test were used to evaluate the recovery of hindlimb locomotor function.The expression of brain-derived neurotrophic factor （BDNF） and neurotrophin-3 （NT-3） in the spinal cords was detected with immunohistochemical methods. Results Nine weeks post-operation, hindlimb locomotor function had improved significantly more in the underwater PBWSTT group than in underwater training group or the BWSTT group.The expression of BDNF in the 3 training groups was significantly higher than in the model control group, though there was no significant difference among the 3 training groups. The expression of NT-3 in the underwater PBWSTT group increased more significantly than in the BWSTT group, however there was no significant difference between the underwater PBWSTT group and the underwater training group. Conclusion Underwater PBWSTT can promote the recovery of hindlimb locomotor function in rats after SCI, probably through increasing the expression of BDNF and NT-3 and thus promoting neural plasticity in the spinal cord.