序贯应用他克莫司后处理与康复训练治疗脊髓缺血再灌注损伤的疗效观察

The neuroprotective effect of tacrolimus postconditioning combined with rehabilitation training in spinal cord ischemia-reperfusion injury in rats

目的观察他克莫司后处理联合康复训练对大鼠脊髓缺血再灌注损伤的保护效应。方法采用随机数字表法将60只雄性SD大鼠分为后处理组、康复训练组、序贯治疗组及模型组。采用经股动脉置管球囊扩张术将各组大鼠制成脊髓缺血模型，模型组在脊髓缺血20min后行再灌注；后处理组及序贯治疗组在再灌注即刻经左颈总动脉按每千克体重0．5mg一次性注射他克莫司；康复训练组与序贯治疗组于再灌注1d时开始进行康复训练。于再灌注2d时采用黄嘌呤氧化酶法测定各组大鼠脊髓内超氧化物歧化酶（SOD）活性，采用硫代巴比妥酸法测定丙二醛（MDA）含量；于再灌注7d、14d及28d时采用BBB评分对各组大鼠后肢运动功能进行评定；于再灌注7d时观察各组大鼠受损脊髓病理改变。结果再灌注2d时序贯治疗组脊髓组织内SOD活性为（139．94±13．41）U／mg prot，明显高于其他各组水平（均P〈0．05），其中后处理组SOD活性为（122．42±10．36）U／mg prot，显著高于康复训练组[（102．67±13．86）U／mg prot]和模型组[（99．72±12．77）U／mg prot]（P〈0．05）；序贯治疗组MDA含量为（7．01±0．93）nmol／mgprot，明显低于其他各组水平（均P〈0．05），其中后处理组和康复训练组MDA含量分别为（8．38±1．03）nmol／mg prot、（8．40±O．55）nmol／mg prot，均显著低于模型组水平[（9．87±1．32）nmol／mg prot]（均P〈0．05）。再灌注28d时序贯治疗组、后处理组及康复训练组BBB评分分别为（18．23±1．14）分、（16．11±1．03）分和（14．80±1．83）分，均显著优于模型组水平[（11．62±1．92）分]（均P〈0．01），其中序贯治疗组BBB评分亦显著优于后处理组及康复训练组（均P〈0．05）。序贯治疗组大鼠受损脊髓病变程度较轻，后处理组及康复训练组次之，模型组病变程度最严重。结论序贯应用他克莫司后处理与康复训练治疗脊髓缺血再灌注损伤具有协同效应，能进一步抑制机体脂质过氧化，促进肢体运动功能恢复。

Objective To investigate any neuroprotective effect when tacrolimus postconditioning is combined with rehabilitation training after spinal cord ischemia-reperfusion injury. Methods Sixty male Sprague-Dawley rats were randomly divided into a tacrolimus postconditioning group, a rehabilitation training group, a sequential therapy group and a model control group. A model of spinal cord ischemia was prepared by means of catheterization through the femoral artery and balloon dilatation. The model control group underwent reperfusion 20 min after the spinal cord ischemia. The tacrolimus posteonditioning and sequential therapy groups received a single injection of tacrolimus （0.5 mg/kg） through the left common carotid artery at the onset of reperfusion. The rehabilitation training and sequential therapy groups received rehabilitation training 1 d after reperfusion. Superoxide dismutase （SOD） activity and malondialdehyde （MDA） level were measured in spinal cord tissues using the xanthineoxidase and thiobarbituric acid （TBA） methods, respectively, 2 d after reperfusion. The Basso, Beattie, and Bresnahan BBB scale was used to assess hindlimb locomotor function at 7, 14 and 28 d after reperfusion. Histopathological changes in the spinal cord tissues were determined using hematoxylin eosin staining 7 d after reperfusion. Results SOD activity in the sequential therapy group was significantly higher than in the other three groups, and the average SOD activity of the tacrolimus postconditioning group was significantly higher than that of the rehabilitation training and model control groups 2 d after reperfusion. The average MDA level of the sequential therapy group was significantly lower than those of the other three groups, with the MDA levels of the tacrolimus postconditioning and rehabilitation training groups significantly lower than that of the model control group 2 d after reperfusion. The locomotor function scores of the sequential therapy group were significantly superior to those of the tacrolimus postconditioning and rehabilitation training groups 14 and 28 d after reperfusion, and the average scores of the latter two groups were significantly higher than that of the model control group 7, 14, and 28 d after reperfusion. The pathological changes in the spinal cord tissue of the sequential therapy group were not so serious as those observed in the tacrolimus postconditioning and rehabilitation training groups. The pathological changes of the control group were the most serious. Conclusion Tacrolimus postconditioning combined with rehabilitation training can exert a synergistic neuroprotective effect after spinal cord ischemiareperfusion injury, at least in rats. It can thus further inhibit lipid peroxidation and promote the recovery of locomotor function.