低剂量他克莫司治疗大鼠急性脊髓损伤的实验研究

目的：探讨低剂量他克莫司（tacrolimus，又名FK506）对大鼠急性脊髓损伤是否具有神经保护作用。方法：雄性Wistar大鼠72只，随机分为假手术组（12只）、损伤组（30只）和FK506治疗组（30只）。采用Allen’s打击法致伤大鼠T10脊髓，假手术组仅做椎板切除术。FK506治疗组在脊髓损伤后5min一次性经尾静脉注射FK5060．3mg／kg，其余两组以相同方法给予等量生理盐水。致伤后30min、6h、24h、48h、72h取伤段脊髓组织行病理观察及原位末端标记法（TUNEL）检测神经细胞凋亡，伤后1、3、7、14、21d行脊髓功能BBB评分和斜板实验。结果：伤后3、7、14、21d，FK506治疗组斜板实验和BBB评分明显优于损伤组，两组间比较差异有显著性（P〈0．05）；伤后各时间点FK506治疗组脊髓损伤区出血坏死较损伤组轻；伤后6、24、48、72h神经细胞凋亡FK506治疗组较损伤组明显减少，两组间比较差异有显著性（P〈0．05）。结论：在大鼠急性脊髓损伤后早期应用低剂量他克莫司（0．3mg/kg）治疗对神经具有保护作用，可减少神经细胞凋亡，减轻脊髓继发性损伤，促进脊髓功能恢复。     

他克莫司对大鼠急性脊髓损伤后细胞凋亡及热休克蛋白70表达的影响

目的探讨脊髓损伤后他克莫司（FK506）对热休克蛋白70表达的影响及其与神经细胞凋亡的关系。方法采用Allen法建立大鼠急性脊髓损伤模型。雄性Wistar大鼠72只,随机分为假手术组（n=12）、损伤组（n=30）和FK506组（n=30）。FK506组伤后5min一次性经尾静脉注射FK506（0．3mg／kg）,假手术组和损伤组以相同方法给予0．9％的生理盐水。术后行脊髓功能评分;逆转录聚合酶链反应（RT—PCR）检测热休克蛋白70mRNA的表达;免疫组织化学染色检测半胱氨酸天冬氨酸蛋白酶-3和热休克蛋白70的表达;原位末端标记法（TUNEL）检测神经细胞凋亡。结果热休克蛋白70mRNA和蛋白的表达在FK506组较损伤组明显增加（P〈0．05）,分别于伤后6、24h达高峰;FK506组半胱氨酸天冬氨酸蛋白酶-3的表达和神经细胞凋亡均较损伤组明显减少（P〈0．01,P〈0．05）;脊髓功能评分在FK506组显著优于损伤组（P〈0．05）。结论FK506能抑制脊髓损伤后半胱氨酸天冬氨酸蛋白酶-3的活性,减轻神经细胞凋亡,促进脊髓功能恢复,其机制可能与诱导热休克蛋白70表达增加有关。     

硫酸软骨素酶ABC对大鼠急性脊髓损伤后神经中丝和胶质纤维酸性蛋白的影响

目的：探讨硫酸软骨素酶ABC（ChABC）对大鼠急性脊髓损伤后神经中丝200（NF200）和胶质纤维酸性蛋白（GFAP）的影响.方法：SD大鼠72只,雌雄不限,随机分为假手术组（A组）、损伤对照组（B组）和ChABC治疗组（C组）,每组24只.A组仅打开椎板及置管,不损伤脊髓,不给药;C组和B组均采用Allen＇s法制作大鼠T10脊髓损伤模型,分别在伤后即刻和随后每天1次连续1周蛛网膜下腔注射ChABC（6μl/次）和等量生理盐水.术后1d、1周、2周和4周每组各处死6只大鼠,B组和C组以损伤区为中心、A组在相应部位切取1cm长的脊髓组织,以HE染色观察脊髓组织形态变化,应用免疫组化方法检测脊髓组织中NF200和GFAP的变化.结果：HE染色示A组脊髓无胶质细胞增生和胶质瘢痕形成;B、C组脊髓损伤区有胶质细胞增生和胶质瘢痕,C组明显少于B组.A组术后1d、1周、2周和4周时NF200阳性细胞数及灰度值和GFAP染色阳性面积无差异,1、2、4周时B、C组脊髓损伤区NF200染色阳性细胞数及灰度值和GFAP染色阳性面积均较A组显著增加（P＜0.05或P＜0.01）,1d和1周时C组NF200染色阳性细胞数及灰度值与B组比较无显著性差异,2周和4周时C组明显高于B组（P＜0.05）;1d、1周和4周时C组GFAP染色阳性面积与B组无显著性差异,2周时C组显著小于B组（P＜0.05）.结论：ChABC能提高大鼠急性脊髓损伤后神经细胞内NF200的表达并抑制GFAP的表达,进而促进神经细胞的修复,抑制胶质细胞的增生和胶质瘢痕的形成,对脊髓损伤具有保护作用.     

丙戊酸对大鼠脊髓损伤后内源性神经干细胞的影响

目的：探讨丙戊酸（valproic acid,VPA）对大鼠脊髓损伤后内源性神经干细胞的影响.方法：45只Wister成年大鼠,随机分为正常对照组（A组,n=5）、单纯损伤组（B组,n=20）、损伤后VPA治疗组（C组,n=20）.B组和C组采用Allen＇s打击模型（25gcm）,在T10段造成急性脊髓损伤,C组损伤后半小时给予VPA治疗,每日300m/kg,经腹腔分两次注射,直至取材;B组以相同方法给予等量生理盐水.于损伤后1d、3d、1周、4周、8周进行取材,对距离损伤中心5mm处脊髓进行巢蛋白Nestin免疫组化检测,应用图像分析软件进行Nestin阳性区域面积测算.结果：A组脊髓室管膜细胞中极少数细胞胞浆内有Nestin表达,白质中几乎无表达.B组损伤后24h Nestin表达于室管膜以及软膜,1周达到高峰（P＜0.05）,并相向延伸至脊髓白质和灰质;损伤后4周Nestin表达明显下降,8周时很少或几乎无表达.C组Nestin表达在伤后24h与B组无显著性差异,1周时在中央管周围Nestin阳性细胞明显较B组多（P＜0.05）,持续至4周时仍高表达,8周时仍有表达.结论：VPA在大鼠脊髓损伤后能够激活内源性神经干细胞.     

脊髓损伤后低剂量FK506对伤段组织电解质水含量失衡的早期保护作用

[目的]探讨脊髓损伤后早期应用低剂量抗移植排斥药物—FK506对伤段脊髓组织钙、镁离子及水含量的影响,明确其神经保护作用的可能机制。[方法]35只雄性Wistar大鼠随机分为对照组、损伤组和治疗组。采用Allen＇s打击法制作脊髓损伤模型,对照组仅做椎板切除术。治疗组在脊髓损伤后5min一次性经尾静脉注射FK506（0.3mg/kg）,其余两组以相同方法给予0.9%的生理盐水。术后6、12、24h取材,采用干湿法测定伤段脊髓组织水含量,以原子吸收光谱分析法测定钙、镁离子含量。[结果]伤段脊髓组织中水含量及钙离子水平升高,两者均于伤后12h达高峰,而镁离子水平降低,应用FK506可显著改善上述变化（P〈0.05,P〈0.01）。[结论]低剂量FK506可减轻伤段脊髓组织水肿和电解质失衡,对继发性脊髓损伤具有神经保护作用。     

川芎嗪对预防犬急性脊髓损伤神经保护作用的实验研究

目的研究川芎嗪对犬急性脊髓损伤模型的神经保护作用。方法Allen’s法打击犬胸13节段脊髓制成急性脊髓损伤模型，所有动物均行介入下选择性动脉插管至伤椎水平肋下动脉，留置导管作为局部给药途径。实验动物随机分为正常对照组、脊髓损伤组、川芎嗪治疗组。术后采用胥少汀脊髓功能评分标准对脊髓神经功能进行评分、MRI检查、血清和脑脊液中髓鞘碱性蛋白(MBP)和S-100B蛋白的测定来衡量脊髓损伤程度和药物治疗效果。结果川芎嗪治疗组在各时间点的神经功能评分高于脊髓损伤组并且在1W有统计学意义。核磁共振检查发现川芎嗪治疗组的相对信号值低于脊髓损伤组，在72h、1W有统计学意义。川芎嗪治疗组血清和脑脊液中MBP低于脊髓损伤组，并且MBP在72h时差异有显著性。结论川芎嗪对于急性脊髓损伤具有神经保护作用。     

甲基强的松龙对大鼠急性脊髓损伤后Nogo-A表达的影响

目的：探讨大剂量甲基强的松龙（MP）对急性脊髓损伤（SCI）大鼠脊髓组织中Nogo-A蛋白表达的影响。方法：将56只成年SD大鼠分为正常对照组（A组,n=8）、急性脊髓损伤组（B组,n=24）和急性脊髓损伤后大剂量MP治疗组（C组,n=24）,C组在损伤后早期从尾静脉注射大剂量MP治疗。分别在术后3、7、14d对B、C组大鼠后肢运动功能行BBB评分,再在各时间点处死动物,取受损节段脊髓行HE染色及免疫组化染色观察形态学变化和Nogo-A在脊髓组织中的分布特点;同时应用Western-blot方法测定各组相应时间点Nogo-A表达量,并与A组比较。结果：B、C组大鼠在损伤后各个时间点后肢运动功能均有一定程度的恢复,Nogo-A蛋白在各组大鼠脊髓组织中均呈阳性表达,分布于神经细胞的细胞浆和脊髓神经纤维周围呈包裹神经纤维的状态。B、C组各个时间点Nogo-A表达均显著高于A组（P〈0.05）,7d时最高,14d时的表达量仍高于正常组;C组在各个时间点的表达量显著低于B组,差异有显著性（P〈0.05）。结论：大鼠急性脊髓损伤后Nogo-A显著升高,早期应用大剂量MP对Nogo-A的表达具有明显的抑制作用。     

核转录因子—κB在FK506保护肝脏缺血再灌注损伤中的作用

目的 研究FK506能否抑制缺血再灌注损伤肝脏核转录因子—κB(NF—κB)的结合活性。方法 采用大鼠部分肝血供被阻断的缺血再灌注损伤模型，左半肝缺血90min，再灌注分0、30min，1、2、4h等时点。实验组术前静脉注射FK506(0．3mg／kg体重)，观察对照组、缺血再灌注组及FK506处理组间肝组织中NF—κB的结合活性(凝胶滞留电泳方法)。结果 肝脏缺血再灌注损伤时，NF—κB与其特异性调控序列的结合活性增高且具有时相性，再灌注1一2h NF—κB结合活性较强，再灌注4h NF—κB结合活性减弱。FK506可以抑制NF—κB与其特异性调控序列的结合活性。结论 FK506通过抑制NF—κB的结合活性改善肝脏缺血再灌注损伤。     

硫氧还蛋白对大鼠急性脊髓损伤后Nogo-A表达的影响

目的 观察经硬膜外注入硫氧还蛋白(Trx)对大鼠急性脊髓损伤(ASCI)后脊髓组织中Nogo-A表达的影响,探讨其对脊髓损伤的保护作用.方法 成年Wister大鼠56只,分为假手术组(A组,n=8)、损伤对照组(B组,n=24)和Trx治疗组(C组,n=24).B、c组用改良Allen's法以30 g/cm致伤大鼠T8脊髓制作损伤模型,同时在蛛网膜下腔置管,C组术后即刻和随后每天1次按0.75mg/kg从硬膜下导管推入硫氧还蛋白,B组在相同时问点给予等量生理盐水;A组打开椎板后蛛网膜下腔置管,不损伤脊髓,不给药.在术后3、7、14 d分别对其进行后肢运动功能BBB评分(n=8),评分完毕即处死动物,取受损节段脊髓组织行免疫组织化学观察脊髓组织中Nogo-A阳性细胞的表达,同时计数阳性细胞.结果 各时间点B组大鼠BBB评分均显著低于A组(P<0.01),伤后7、14 d时C组评分显著高于B组(P<0.05或0.01).B组在术后7与14日Nogo-A表达均显著高于A组(P<0.01);C组在伤后7、14 d的表达量显著低于B组,差异有统计学意义(P<0.05).结论 大鼠急性脊髓损伤后Nogo-A显著升高,Trx能明显抑制Nogo-A的表达,可能促进轴突的再生.     

应用大脑皮层诱发电位建立精确分级脊髓损伤模型

目的 建立脊髓损伤精确分级动物模型.方法 自行设计一种犬的运动-静止压迫型脊髓损伤模型,以大脑皮层诱发电位(CSEP)和不同压迫时间为参数,以T13横突连线为中心,安装大小为0.6 cm×1.0 cm的加压阀,以0.2 mm/min速度压迫脊髓,同时持续性CSEP监测,随压迫深度加深,CSEP波幅不断压低,当波幅下降达基础值的50%时停止下压,继续维持压迫,将20只杂种犬随机分为三组:A组(n=8):脊髓继续受压30 min;B组(n=8):脊髓继续受压180 min;C组(n=4):为对照组,脊髓显露后不损伤.观察电生理学、组织病理学、功能恢复及MRI变化.结果 两组脊髓组织学均有损害、MRI显示两组均有脊髓受压性改变,按照Aiith法计算A、B组的脊髓白质残留面积百分比和MRI脊髓变性空洞区最大横面积百分比,差异均有统计学意义(P<0.05);A组CSEP逐渐恢复达基线的76%,B组CSEP无恢复,C组一直无变化;脊髓受压早期两组均有后肢功能障碍,按照改良的Tarlov测定法和运动能力法评估A、B两组,差异有统计学意义(P<0.05).结论 以CSEP和不同压迫时间为参数,能够建立不同损伤程度的可重复性强的分级脊髓损伤模型.     

The effects of FK506 on neurologic and histopathologic outcome after transient spinal cord ischemia induced by aortic cross-clamping in rats

Spinal cord injury is a devastating complication of thoracoabdominal aortic surgery. We investigated the effect of the immunosuppressant FK506, a macrolide antibiotic demonstrated to have neuroprotective effects in cerebral ischemia models, in a rat model of transient spinal cord ischemia. Spinal cord ischemia was induced in anesthetized rats by using direct aortic arch plus left subclavian artery cross-clamping through a limited thoracotomy. Experimental groups were as follows: sham-operation; control, receiving only vehicle; FK506 A, receiving FK506 (1 mg/kg IV) before clamping; and FK506 B, receiving FK506 (1 mg/kg IV) at the onset of reperfusion. Neurologic status was assessed at 24 h and then daily up to 96 h with a 0 to 6 scale (0, normal function; 6, severe paraplegia). Rats were randomly killed at 24, 48, or 96 h, and spinal cords were harvested for histopathology. Physiologic variables did not differ significantly among experimental groups. All control rats suffered severe and definitive paraplegia. FK506-treated rats had significantly better neurologic outcome compared with control. Histopathologic analysis disclosed severe injury in the lumbar gray matter of all control rats, whereas most FK506-treated rats had less injury. These data suggest that FK506 can improve neurologic recovery and attenuate spinal cord injury induced by transient thoracic aortic cross-clamping. IMPLICATIONS: A single dose-injection of the immunosuppressant FK506 significantly improved neurologic outcome and attenuated spinal cord injury induced by transient thoracic aortic cross-clamping in the rat.     

Immunophilin ligands FK506 and cyclosporine A improve neurologic and histopathologic outcome after transient spinal cord ischemia in rabbits

BACKGROUND: We comparatively evaluated the protective effect of the immunophilin ligands cyclosporine A (INN: ciclosporin), FK506, and rapamycin on the spinal cord in a rabbit model of transient ischemia. Both cyclosporine A and FK506 inhibit calcineurin, whereas rapamycin does not. METHODS: Thirty-six male New Zealand White rabbits were divided into the following 6 groups: group C, 15 minutes of spinal cord ischemia; group FK, FK506 (1 mg/kg) administered 30 minutes before ischemia; group CsA, cyclosporine A (30 mg/kg) administered 30 minutes before ischemia; group CsA-C, chronic administration of cyclosporine A (20 mg/kg) for 9 days before ischemia; group R, rapamycin (1 mg/kg) administered 30 minutes before ischemia; and group R+FK, rapamycin (1 mg/kg) administered 20 minutes before FK506 pretreatment (1 mg/kg). Group CsA-C was added because the drug does not readily cross the blood-brain barrier. Neurologic function was evaluated by Johnson's 5-point scale at 8, 24, and 48 hours after ischemia, and histopathology was assessed 48 hours after ischemia. RESULTS: At 24 and 48 hours after ischemia, the Johnson score was better in groups FK (4.0 +/- 1.1), R+FK (3 +/- 1.1), and CsA-C (2.7 +/- 1.2) than in group C (0.8 +/- 1.2). Numbers of morphologically intact anterior horn cells were higher in groups FK (31.3 +/- 9.9), R+FK (23.2 +/- 4.5), and CsA-C (18.3 +/- 6.8) than in group C (6.3 +/- 4.3). CONCLUSIONS: FK506 and chronic administration of cyclosporine A, but not rapamycin, protect the spinal cord from transient ischemia. Although these results are compatible with inhibition of calcineurin in the mechanism of neuroprotective action of these drugs, other effects through different pathways cannot be excluded before further study.     

Neuroprotective effects of FK-506, L-carnitine and azathioprine on spinal cord ischemia-reperfusion injury.

OBJECTIVE: In our experimental study, we aimed to test the effect of FK506, azathioprine and L-carnitine on protection of spinal cord injury due to ischemia-reperfusion. METHODS: Twenty-seven Sprague-Dawley male rats were randomly divided into five groups. They were subjected to spinal cord ischemia by clamping the abdominal aorta for 45 min. Thirty minutes before the aortic clamping, group I received 0.5 mg/kg FK506, group II received 100 mg/kg L-carnitine, group III received 4 mg/kg azathioprine, the fourth group was the control group and received only normal saline injection intravenously and the last group was the sham group. Neurological status was scored by using the Tarlov scoring system. Sections of the lumbar cord were harvested for histopathological grades (1-4), having regard to percentage of the apoptotic cells. RESULTS: Hind-limb motor function had recovered normally 48 h after the operation in all rats which received FK506, azathioprine and L-carnitine prophylactically. In contrast, all rats in the control group had deteriorated to paraplegia by 48 h after the operation (P<0.05). Histopathologic sections in the involved spinal cord segment showed that a greater number of motor neuron cells were preserved and there were less apoptotic cells in the rats that received FK506, azathioprine and L-carnitine than those in control group. CONCLUSIONS: These results suggest that prophylactic use of FK506, azathioprine and L-carnitine protects motor neuron cells from ischemic spinal cord injury.     

Effectiveness of FK506 on lipid peroxidation in the spinal cord following experimental traumatic injury

STUDY DESIGN: An in vivo study in Wistar albino rats with injured spinal cord. SETTING: Department of Neurosurgery, Biochemistry and Pathology, Gazi University, Ankara, Turkey. OBJECTIVES: The aim of this study was to investigate and compare the effects of FK506 an immunosupressive agent with methylprednisolone (MP) on lipid peroxidation (LP) in injured spinal cord tissue. METHOD: A total of 28 adult healthy Wistar albino rats were subjected to traumatic spinal cord injuries (SCI) by using an aneurysmal clip compression technique, and they were divided into four groups. The G1 group (n=8) received FK506 (1 mg/kg); the G2 group (n=8) received FK506 (1 mg/kg) and MP (30 mg/kg); the G3 group (n=6) received only MP (30 mg/kg); and the G4 group (n=6) received no medication. The injured spinal cord tissue was studied by means of lipid peroxides, malondialdehyde (MDA), with thiobarbituric acid reaction and additionally the FK506 (G1); the MP (G3) groups were studied for histopathologic alterations 72 h after SCI with eight separate animals. RESULTS: Although LP values of G1, G2, G3 showed no statistical difference between intergroup analyses (P=0.547), a histopathological examination revealed that in the group that received MP, the oedema pattern was more significant than the group that received FK506. Another interesting finding was the presence of polymorphonuclear leucocytes in the MP group, whereas no infiltration was found in the FK506 group. CONCLUSION: Analysis of the results indicated that FK506 is a valuable pharmacological agent that could be used to decrease the LP and polymorphonuclear leucocyte infiltration and inflamatory reactions in the injured spinal cord tissue.     

预防使用大剂量甲基强的松龙对大鼠急性脊髓损伤的神经保护作用

目的研究预防使用大剂量甲基强的松龙对急性脊髓损伤大鼠的神经功能保护作用方法采用Allen重物打击模型，动物随机分为三组：对照组；脊髓损伤组；预防使用大剂量甲基强的松龙组。分别在脊髓损伤后24h、72h进行神经功能评分(Tarlov评分障碍率、Molt斜板功能障碍率)、脊髓病理形态学及超微结构观察、神经中丝(NF)及胶质纤维酸性蛋白(GFAP)观察、结果预防使用大剂量MP可明显改善损伤脊髓的病理形态及超微结构；脊髓损伤后72h大鼠神经功能评分明显提高；显著提高NF的表达、抑制GFAP的表达．结论预防使用大剂量甲基强的松龙对大鼠急性脊髓损伤有神经保护作用     

大剂量甲基强的松龙对大鼠急性脊髓半切损伤的早期神经保护作用

目的研究大剂量甲基强的松龙（methylprednisolone,MP）对大鼠急性脊髓半切损伤的早期神经保护作用。方法 50只SD大鼠随机取10只仅行椎板切除,作为对照组。其余40只随机分为2组,脊髓半切损伤组及MP治疗组各20只。各组动物再随机平分为2个小组,分别在脊髓半切损伤后1d、7d进行BBB法神经功能评分、脊髓组织形态学观察、神经中丝（neurofilament NF）和胶质纤维酸性蛋白（glial fibrillary acidic protein,GFAP）免疫组化测定。结果脊髓半切损伤后立即使用大剂量MP明显提高了伤后7d时MP治疗组的BBB评分;对损伤脊髓的组织形态学有明显改善;明显提高了NF的表达,抑制了GFAP的表达。结论早期大剂量使用MP对大鼠急性脊髓半切损伤有神经保护作用。     

Combination use of suboptimal dose of FK 506 and cyclosporine in canine lung transplantation.

The immunosuppressive potency and the side effects of combination therapy with FK 506 and cyclosporine A were studied in dogs that had undergone lung transplantation. The animals were divided into four groups: group A (one third optimal FK 506 dose: FK 506, 0.03 mg/kg intramuscularly) (n = 5), group B (one third optimal cyclosporine dose: cyclosporine 6 mg/kg orally) (n = 5), group C (one third FK 506 and one third cyclosporine optimal doses): FK 506, 0.03 mg/kg intramuscularly plus cyclosporine 6 mg/kg orally) (n = 5), and group D (half FK 506 plus half cyclosporine optimal doses: FK 506, 0.05 mg/kg intramuscularly, plus cyclosporine, 10 mg/kg orally) (n = 10). Assessments including chest x-ray film, fiberoptic bronchoscopy, hematologic and biochemical tests, FK 506 and cyclosporine blood trough level measurement, right pulmonary artery occlusion test, and histopathologic observations were performed. In group A two of five dogs survived 28 days and three died on postoperative days 7, 14, and 21. In group B one dog survived 28 days and four died on postoperative days 9 (two dogs), 14, and 21. Histologic examination showed severe rejection in both group A and group B. In group C all five dogs survived 28 days but showed mild rejection. In group D one dog died of intestinal bleeding on postoperative day 7 and nine survived 28 days. No pathologic changes were observed except in one case of mild rejection. The ventilation function of the transplanted lung was poor in groups A, B, and C but good in group D. No abnormal rise of FK 506 and cyclosporine trough levels was observed. There were no significant side effects and abnormal hematologic and biochemical data except in one dog in group D. We concluded (1) the combination of FK 506, 0.03 mg/kg, and cyclosporine, 6 mg/kg, is much more effective than either drug used singly, (2) the combination of FK 506, 0.05 mg/kg, and cyclosporine, 10 mg/kg, prevents rejection with tolerable side effects, and (3) no worse side effects are caused by combination therapy with FK 506 and cyclosporine than by either one used singly.     

早期联合测定各项生物标志物对评估脊髓损伤的临床意义

目的 探讨早期联合测定各项生物标志物对评价脊髓损伤的临床意义.方法 回顾性分析自2017-01-2018-12诊治的22例脊髓损伤,比较入院时和术后6个月Frankel等级,11例Frankel等级有1个或1个以上级别的改善,定义为B组;11例Frankel等级无改变,定义为C组,并纳入同期20例健康体检者为A组.比较...     

Neuroimmunophilin ligands improve functional recovery and increase axonal growth after spinal cord hemisection in rats

We have previously shown that FK506 accelerates the rate of nerve regeneration in the peripheral nervous system (PNS) and increases regeneration of central nervous system (CNS) axons into a peripheral nerve graft. In the present study, we examined whether FK506 and a nonimmunosuppressive derivative (FK1706) improve functional recovery and long distance regeneration following a hemisection lesion of spinal cord at T10/T11. Rats were given daily subcutaneous injections of either FK506 (2 mg/kg/day), FK1706 (2 mg/kg/day), an equivalent volume of saline or 30% DMSO as vehicle, respectively. Functional recovery was assessed using a modified Tarlov/Klinger scale, walking along progressively narrower wooden beams (7.7-1.7 cm widths), and analysis of footprints obtained during walking. Compared to both control groups, FK506 and FK1706-treated animals demonstrated significant functional recovery 4 days (beam walking), 2 weeks (footprints), and 4 weeks (Tarlov/Klinger scale). By 11 weeks, FK506-treated and FK1706-treated animals were able to walk, albeit poorly, along even the narrowest (1.7 cm) beam. At 11 weeks, the spinal cords were re-exposed and a small piece of gel foam-soaked Fluoro-Gold was placed on the injured side 2-cm caudal to the first injury. Five days later, the animals were perfused and tissues prepared for fluorescence microscopy. FK506-treated and FK1706-treated rats demonstrate a significantly greater number of retrogradely labeled neurons in the red nucleus. The results implicate a nonimmunosuppressant mechanism in FK506's action and suggest that FK506 or a nonimmunosuppressant derivative may be useful for treatment of spinal cord injuries.     

FK506 increases the regeneration of spinal cord axons in a predegenerated peripheral nerve autograft

The authors examined the ability of FK506 to accelerate axonal regeneration of rat spinal cord axons in a peripheral nerve (PN) graft. Predegenerated autografts were produced by transecting the left tibial nerve 1 week prior to spinal cord implantation into the lumbar (L-3-L-4) spinal cord. Rats were given daily injections of either FK506 (5 mg/kg, subcutaneous) or vehicle for 21 days. The PN grafts from FK506-treated rats contained larger sized regenerating axons compared with vehicle-treated controls, and mean axonal areas increased by 25% at 7.5 mm along the PN graft. Fluoro-Gold retrograde labeling confirmed that the regenerating axons originated from the central nervous system. Unexpectedly, the majority (>50%) of neurons in the red nucleus were retrogradely labeled in the FK506-treated animals only. The results indicate that FK506 not only accelerates the elongation of spinal cord axons but also promotes regeneration of rubrospinal neurons.