目的：探索丹参酮 IIA 对脊髓挫伤大鼠后肢神经功能恢复的影响及其作用机制。方法将45只 SD 大鼠随机分为4组(对照组、模型组、丹参酮 IIA 组、甲泼尼龙组)：对照组(仅切除椎板，尾静脉注射生理盐水1 ml /天，连续7天)。模型组(使用 NYU 脊髓打击器选择25 mm 高度造成 T9脊髓节段挫伤，术后予尾静脉注射生理盐水1 ml /天，连续7天)。丹参酮 IIA 组(造模成功后即刻予尾静脉注射丹参酮 IIA 磺酸钠注射液20 mg / kg /天，连续给药7天)。甲泼尼龙组(造模成功后即刻予尾静脉注射甲泼尼龙30 mg / kg，仅给药1次)。采用旷场实验[ Basso，Beattie，and Bresnahan ( BBB ) open field locomotor test ]和热板实验评价各组大鼠后肢神经功能的恢复。在术后1、4、8周进行心脏灌注固定并取材 T9脊髓，HE 染色、尼氏染色观察挫伤脊髓局部组织结构的变化，同时通过免疫组化法标记各组脊髓中的巨噬/小胶质细胞。结果(1)术后3天，丹参酮 IIA 组(1.91±0.31)和甲泼尼龙组(3.10±0.41)大鼠后肢运动功能较模型组(0.89±0.26)都有显著改善，且甲泼尼龙组改善更明显( P＜0.05)；至术后8周，甲泼尼龙组(17.00±0.41)运动功能改善仍然较丹参酮 IIA 组(15.50±0.43)更明显，差异有统计学意义( P＜0.05)；(2)术后3天，甲泼尼龙组(4.06±0.26)感觉功能恢复较丹参酮 IIA 组(4.59±0.71)快，差异有统计学意义( P＜0.05)；术后2周开始，丹参酮 IIA 组(3.06±0.13)表现出了比甲泼尼龙组(3.14±0.13)更明显的改善趋势，但差异无统计学意义( P＞0.05)；(3)术后1周，除对照组，余各治疗组部分巨噬/小胶质细胞形态由分支状变为杆状或圆状，其中丹参酮 IIA 组和甲泼尼龙组形态改变的细胞较少，丹参酮 IIA 组(11.61±2.64)和甲泼尼龙组(11.88±1.47)阳性细胞累积光密度( integrated optical density，IOD )较模型组(27.22±3.04)明显减少，差异有统计学意义( P＜0.05)；(4)术后8周，除对照组，余各组巨噬/小胶质细胞形态大部分转变为分枝状，其中丹参酮 IIA 组(2.89±0.12)和甲泼尼龙组(2.93±0.15)大鼠阳性细胞 IOD 较模型组(1.58±0.20)明显增加，差异有统计学意义( P＜0.05)。结论(1)丹参酮 IIA 能够促进脊髓损伤大鼠后肢运动、感觉功能恢复；(2)丹参酮 IIA 能够促进巨噬/小胶质细胞对神经恢复的有利影响。“,”Objective To determine the impact of tanshinone IIA ( TIIA ) on the recovery of hindlimb neurological disorders and to explore the possible mechanisms. Methods Adult female Sprague-Dawley rats ( n = 45 ) were randomly divided into 4 groups: Sham group ( laminectomy only ), SCI group ( T9 spinal cord contusive injury ), SCI / TIIA group ( SCI with intravenous injection of TIIA [ 20 mg / kg ] from 1 to 7 days post-injury at the same time ), SCI / MP group ( SCI with intravenous injection of methylprednisolone [ 30 mg / kg ] once post-injury ). SCI was generated by using NYU injury device with a 10-g weight dropped from a height of 25 mm. Sham group and SCI group were treated with intravenous injection of 1 ml normal saline from 1 to 7 days post-injury at the same time. ( 1 ) Spontaneous locomotion and sensory function of all animals were assessed by the Basso, Beattie, and Bresnahan ( BBB ) open field locomotor test and hot plate test. Transcardiac perfusion fixation were done at 1, 4 and 8 weeks post-SCI. Sections of T9 spinal cord were collected. Then the T9 spinal cord tissue stained with Cresyl Violet for Nissl staining and stained with hematoxylin and eosin for HE staining. Microglia in the injured spinal cord were marked by immunohistochemistry at 7 days and 8 weeks post-SCI. Results ( 1 ) Hindlimb motor function of TIIA group ( 1.91 ± 0.31 ) and MP group ( 3.10 ± 0.41 ) was significantly improved 3 days post-surgery, but MP group was more effective ( P < 0.05 ); at 8 weeks post-surgery, hindlimb motor function of MP group ( 17.00 ± 0.41 ) was still more effective than in TIIA group ( 15.50 ± 0.43 ) ( P < 0.05 ). ( 2 ) Sensory function of MP group ( 4.06 ± 0.26 ) recovered faster than TIIA group ( 4.59 ± 0.71 ) 3 days post-surgery, and the difference was statistically significant ( P 0.05 ). ( 3 ) In each group, except sham group, microglia contract their processes and transformed from a ramified to an ameboid morphology at 7 days post-surgery. Changes of morphology in TIIA group and MP group were relatively smaller, but the integrated optical density ( IOD ) of macrophage / microglia in TIIA group ( 11.61 ± 2.64 ) and MP group ( 11.88 ± 1.47 ) was reduced significantly compared with SCI group ( 27.22 ± 3.04 ), and the difference was statistically significant ( P < 0.05 ). ( 4 ) In each group, except sham group, microglia transformed from an ameboid to a ramified morphology at 8 weeks post-surgery. The IOD of macrophage / microglia increased in TIIA group ( 2.89 ± 0.12 ) and MP group ( 2.93 ± 0.15 ) compared with SCI group ( 1.58 ± 0.20 ), and the difference was statistically significant ( P < 0.05 ). Conclusions ( 1 ) TIIA possibly promotes the recovery of motor and sensory function of hindlimb in rats after SCI. ( 2 ) TIIA plays a positive role in the recovery of neurological disorder by influencing the macrophage / microglia.