他克莫司对犬急性脊髓损伤神经保护作用的实验研究

目的探讨他克莫司（FK506）对犬急性脊髓损伤的神经保护作用。方法采用Allen＇s法制成犬急性脊髓损伤实验模型。动物随机分为：A组（n=8）,经动脉插管注入生理盐水;B组（n=8）,FK5060.18mg／kg;C组（n=8）．FK5060.3mg／kg。B组、C组均在致伤后2h经动脉插管单次给药。致伤后行脊髓MRI影像学检查、脊髓功能评分、脊髓组织病理观察、神经丝蛋白（NF200）及胶质纤维酸性蛋白（GFAP）的免疫组织化学分析。结果脊髓功能评分C组优于A组（P〈0.05）;B组优于A组,但无统计学差异;MRI显示：脊髓损伤后C组病变范围小,恢复快,B组次之．A组最差。C组NF和GFAP表达高于A组（P〈0.05）,B组与A组无统计学差异。结论局部应用FK506（0.3mg／kg）对急性脊髓损伤具有神经保护作用,可减轻继发损伤,加快脊髓功能的恢复;局部应用FK506对急性脊髓损伤治疗有一定的剂量-效应依赖关系。     

Effect of methylprednisolone, tirilazad mesylate and vitamin E on lipid peroxidation after experimental spinal cord injury

Effect of methylprednisolone (MP), tirilazad mesylate (TM) and vitamin E on lipid peroxidation (LP) was evaluated in an experimental model of spinal cord compression injury in anesthetized rats. Forty rats, divided randomly into four groups, were injured by compressing on the spinal cord at Th 3 for 1 min. Bolus injections of saline solution, MP (30 mg/kg bolus and 5.4 mg/kg/h), TM (10 mg/kg four times per day), or vitamin E (30 mg/ kg four times per day) were begun 1 h after the spinal cord injury (SCI). Twenty-four hours after treatment, the rats were killed, and malondialdehyde (MDA), a LP product, was measured in the spinal cord tissues. Rats treated with MP, TM and vitamin E had significantly decreased MDA levels (P<0.01) than rats in the control group. The lowest MDA levels were found in the TM group. These results suggest that MP, TM and vitamin E may have a protective effect against SCI in rats by its antioxidant effect.     

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.     

甲基强的松龙对大鼠脊髓损伤后GFAP、neurocan和phosphacan表达的影响

目的观察甲基强的松龙(MP)对大鼠脊髓损伤(SCI)后GFAP、neurocan和phosphacan表达的作用.方法36只成年Wistar大鼠随机分为3组,其中正常对照组4只,损伤组和治疗组各16只.正常对照组大鼠不损伤脊髓,治疗组大鼠采用局部压迫法损伤T9脊髓,损伤后立即尾静脉推注MP 30mg/kg,随后24h内每间隔6h推注MP(30mg/kg)一次,共给药5次.损伤组以同样方法损伤脊髓并推注等量生理盐水.分别于伤后3d、7d及14d切取损伤处脊髓标本,行RT-PCR及免疫组化检测GFAP、neurocan和phosphacan mRNA相对含量和蛋白表达.结果大鼠SCI后GFAP、neurocan和phosphacan mRNA相对含量增加.伤后3d、7d、14d,MP治疗组比损伤组GFAP mRNA含量均明显减少(P＜0.01);伤后3d、7d治疗组neurocan和phosphacan mRNA含量减少(P＜0.01);至伤后14d时含量改变不明显(P＞0.05).结论SCI后MP能抑制大鼠GFAP、neurocan和phosphacan表达.     

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.     

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。     

Effects of dexmedetomidine or methylprednisolone on inflammatory responses in spinal cord injury

Background: The aim of this study was to compare the anti-inflammatory response of methylprednisolone and the α2-agonist dexmedetomidine in spinal cord injury (SCI).
Methods: Twenty-four male adult Wistar albino rats, weight 200–250 g, were included in the study. The rats were divided into four groups as follows: the control group ( n : 6) received only laminectomy; the SCI group ( n : 6) with trauma alone; the SCI+methylprednisolone group ( n : 6) with trauma and 30 mg/kg methylprednisolone, followed by a maintenance dose of 5.4 mg/kg/h; and the SCI+dexmedetomidine group ( n : 6) with trauma and 10 μg/kg dexmedetomidine treatment intraperitoneally. Twenty-four hours after the trauma, spinal cord samples were taken for histopathological examination and serum samples were collected for interleukin-6 (IL-6) and tumor necrosis factor (TNF)-α measurement.
Results: TNF-α ( P =0.009) and IL-6 ( P =0.009) levels were significantly increased in the SCI group. TNF-α and IL-6 levels were significantly decreased with methylprednisolone ( P =0.002, 0.002) and dexmedetomidine ( P =0.002, 0.009) treatment, respectively. Methylprednisolone and dexmedetomidine treatment reduced neutrophils' infiltration in SCI.
Conclusions: The current study does not clarify the definitive mechanism by which dexmedetomidine decreases inflammatory cytokines but it is the first study to report the anti-inflammatory effect of dexmedetomidine in SCI. Further studies are required to elucidate the effects of dexmedetomidine on the inflammatory response.     

Synergistic neuroprotective effects of hyperbaric oxygen and methylprednisolone following contusive spinal cord injury in rat

ObjectiveRecent studies revealed the neuroprotective effects of hyperbaric oxygen (HBO) on spinal cord injury (SCI). Meanwhile, the use of methylprednisolone (MP) is one of the current protocols with limited effects in SCI patients. Accordingly, the aim of the present study was to investigate the effect of combined HBO and MP treatment on SCI.DesignThe present study was conducted on five groups of rats each as follows: Sham group (underwent laminectomy alone at T9 level vertebra); SCI group (underwent moderate contusive SCI); MP group (underwent SCI and received MP); HBO group (underwent SCI and received HBO); HBO + MP group (underwent SCI and simultaneously received MP and HBO). Blood serum and Spinal cord tissue samples were taken 48 h after SCI for analysis of serum ferric reducing antioxidant power (FRAP) and tissue malodialdehyde (MDA) levels as well as immunohistochemistry of caspase-3 and tumor necrosis factor-alpha (TNF-α). Neurological function was evaluated by the Basso–Beattie–Bresnehan (BBB) locomotion scores until the end of experiments. Additionally, histopathology was assessed at the end of the study.SettingMazandaran University of Medical Sciences, Sari, Iran.ResultsCombination therapy with HBO and MP in the HBO + MP group significantly decreased MDA as well as increased FRAP levels compared to other treatment groups. Meanwhile, attenuated TNF-α and Caspase-3 expression could be significantly detected in the HBO + MP group. At the end of treatment, the neurological outcome was significantly improved and the extent of injured spinal tissue was also significantly reduced in the HBO + MP compared to other treatment groups.ConclusionThe results suggest that combined therapy with MP and HBO has synergistic effects on SCI treatment.     

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.     

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.     

Changes of free iron contents and its correlation with lipid peroxidation after experimental spinal cord injury

Objective: To observe the dynamic changes of free iron contents and its relationship to the changes of lipid peroxidation after experimental spinal cord injury (SCI). Methods: Sprague Dawley rats were randomly divided into three groups: Group A (n=6) received no operation; Group B (n=48) received only laminectomy (sham) ; and Group C (n=48) received both laminectomy and traumatic injury ( SCI model). The SCI animal models were made by using an modified Alien‘s weight-drop device (50 g. cm) on T12. Rats were sacrificed at 0.5, 1, 3, 6, 12, 24 hours after injury. The levels of free iron involved in spinal cord segments at different time points were measured by blcomycin assay. The malondialdehyde (MDA) was also measured by the thiobarbituric acid (TBA). Results: After SCI in Group C, the level of free iron showed a significant increase at 0.5 hour compared to Groups B and A, restored to the control level at 6 h; the level of MDA was increased at 0.5 hour, peaked at 3 hours, returned to the control level at 12 hours; the concentrations of free iron and lipid peroxidation in injured rats were significantly and positively correlated at 0.5-3 hours. Conclusions: After SCI the levels of free iron are increased quickly and might be a major contributor to lipid peroxidation in injured spinal cord.     

Synergistic effect of vincristine with tacrolimus or sirolimus in prevention of acute heart allograft rejection in the rat

The application of multiple immunosuppressive therapy for organ transplantation could enhance therapeutic efficacy, while minimizing the toxicity of individual drugs used in the regimen. In this study, the effect of the combined therapy of vincristine (VCR) with tacrolimus (FK506) or sirolimus (rapamycin, RAPA) was tested in prevention of acute heart allograft rejection in the rat. A Brown Norway (BN, RT 1(n)) to Lewis (LEW, RT 1(1)) rat combination was used in a heart allografting model. VCR was administered intraperitoneally once daily, while FK506 and RAPA were given by gavage once daily for 14 days after transplantation. There were dose-related prolongations of mean survival time (MST) to monotherapy of VCR, FK506, or RAPA. The MST in combination therapy indicated that a synergistic interaction was produced when compared with the respective monotherapies: VCR 0.05 mg/kg/day + FK506 0.5 mg/kg/day (16.00 +/- 1.79 days, P = 0.001; combination index (CI) = 0.557); VCR 0.05 mg/kg/day + FK506 1.0 mg/kg/day (29.00 +/- 10.54 days, P = 0.001; CI = 0.598); VCR 0.05 mg/kg/day + RAPA 0.2 mg/kg/day (17.33 +/- 1.97 days, P = 0.001; CI = 0.500); and VCR 0.05 mg/kg/day + RAPA 0.4 mg/kg/day (21.17 +/- 3.19 days, P = 0.001; CI = 0.838). Combination therapy of VCR and FK506 or RAPA produced synergistic effects in prevention of acute heart allograft rejection in the rat.     

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.     

辛伐他汀促进脊髓损伤后神经功能修复的实验研究

目的:探讨脊髓损伤后急性期应用辛伐他汀对大鼠脊髓神经功能修复的影响。方法:成年雌性SD大鼠32只,假手术组(A组)8只,只做椎板切除,不损伤脊髓,不给药,重物坠落法制作脊髓损伤模型24只,损伤大鼠随机分为三组:羧甲基纤维素钠溶液组(B组)、5mg/kg辛伐他汀治疗组(C组)和10mg/kg辛伐他汀治疗组(D组)(n=8)。术后1d开始灌胃给予辛伐他汀每天一次,连续治疗5周。术后1d、3d以及1～8周,进行BBB评分、斜板试验评价大鼠脊髓神经功能,在第8周时电生理检测大鼠运动及感觉功能的恢复情况,随后处死取材,病理学检查(Luxol fast blue染色)观察残余髓鞘情况。结果:术后2周时,BBB评分D组高于B组(P<0.05);建模3周～8周,BBB评分D组及C组均高于B组(P<0.05),且D组最高(P<0.05)。建模3周时,斜板试验D组及C组均大于B组(P<0.05),且4周～8周,D组角度均大于C组(P<0.05)。感觉诱发电位检查发现,D组,C组的潜伏期小于B组(P<0.05),且D组波幅高于B组(P<0.05)。病理学检查,D组,C组比B组有更多的髓鞘残余(P<0.05)。结论:辛伐他汀急性期治疗脊髓损伤可以促进大鼠损伤脊髓神经功能修复。     

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.     

Mycophenolate mofetil significantly reduces leukocyte graft infiltration after heterotopic cardiac transplantation in a rat model: comparative study with cyclosporine and FK 506.

BACKGROUND: The purpose of the study was to evaluate the effects of cyclosporine (CsA), FK 506 and mycophenolate mofetil (MMF) on graft-infiltrating leukocytes (CD4, CD8, CD11a, CD18) after cardiac transplantation in rats. METHODS: Three hundred forty animals were transplanted and randomly divided into 4 groups: CsA, 3 mg/kg/d (n = 74); MMF, 40 mg/kg/d (n = 96); FK 506, 0.3 mg/kg/d (n = 96); and a control group receiving no immunosuppressive therapy (n = 74). Three or 4 animals from each group were killed at intervals of 1 to 4 days up to Day 60. Immunohistochemistry was performed using monoclonal antibodies (MAb) against CD4, CD8, CD11a and CD18. Positively stained cells were analyzed in the perivascular space (PVS) of intra- and epicardial arteries. Statistical analysis was performed using area-under-the-curve assessment with an extended t-test. RESULTS: CsA and FK 506 reduced the presence graft-infiltrating leukocytes (CD4, CD8, CD11a, CD18) in the PVS of intra- and epicardial arteries when compared with control animals. MMF therapy resulted in a further significant reduction in infiltrating leukocytes when compared with the 2 calcineurin inhibitors. MMF had a faster onset of action than the calcineurin inhibitors. CsA and FK 506 required 12 to 20 additional days to achieve the reducing effect of graft infiltration seen in MMF-treated animals. CONCLUSION: MMF possesses potent infiltration-blocking properties and its application leads to a greater reduction of cellular infiltration in the course of transplant rejection when compared with calcineurin inhibitors.     

慢病毒介导的脑红蛋白体内基因转染对兔损伤脊髓的作用

【摘要】　目的：观察慢病毒介导脑红蛋白（Ngb）体内基因转染兔损伤的脊髓组织后对后肢运动功能的影响,探讨其作用机制。方法：用球囊压迫法制成兔脊髓损伤（ＳＣＩ）模型96只,随机分为对照组（A组）、生理盐水组（B组）、空载体组（C组）和Ngb慢病毒组（D组）,每组动物24只,A组SCI后无治疗;B组SCI后向脊髓内注射生理盐水;C组SCI后向脊髓内注射空病毒;D组SCI后向脊髓内注射Ngb重组慢病毒。各组分别在1、3、7、14、21d采用BBB运动功能评分系统检测兔后肢运动功能情况;观察损伤脊髓组织内标记荧光的表达;Real-time PCR和Western blot检测Ngb mRNA及其相应蛋白的表达情况,生化方法检测丙二醛（MDA）和一氧化氮（NO）水平。结果：损伤后14d和21d,D组BBB评分明显高于其他3组（P<0.05）,但A、B及C组之间比较无差异（P＞0.05）;C组和D组兔损伤部位脊髓组织均有GFP表达的绿色荧光信号;损伤后7d、14d和21d,D组的Ngb表达与其他3组比较明显增强（P<0.05）;损伤后7d、14d和21d,D组损伤脊髓组织中MDA、NO含量明显低于其他3组（P<0.05）。结论：慢病毒介导脑红蛋白（Ngb）体内基因转染可使Ngb高表达,可能是通过减轻继发性SCI,从而促进SCI后后肢运动功能的恢复。     

FK506和供体特异性输血在大鼠异位心脏移植中的作用

目的探讨FK506和供体特异性输血在大鼠异位心脏移植中的作用。方法利用大鼠异位心脏移植模型以了解在移植当天或移植术后第4日进行供者特异性输注（DST）的基础上,应用FK506能否延长移植物的存活。结果在移植当天行DST或单独用FK5061mg／kg连续10天,可将移植心中位存活时间从对照组的5天分别有效延长至7天和11天,而FK506与DST联合应用时并不产生增强效应。结论FK506和DST单独应用时虽均能延长大鼠同种移植心存活,但是它们没有协同作用。     

FK506 Increases the Regeneration of Spinal Cord Axons in a Predegenerated Peripheral Nerve Autograft

Abstract

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.     

Effects of methylprednisolone and MK-801 on functional recovery after experimental chronic spinal cord injury

STUDY DESIGN: An experimental study was conducted to evaluate the effects of methylprednisolone and MK-801 after the compressive injury of spinal cord in rats. OBJECTIVES: To investigate the effect of methylprednisolone and non-competitive NMDA antagonist MK-801 in long-term functional outcome after spinal cord injury (SCI). METHODS: A randomized group A of Sprague-Dawley rats were treated with MK-801 (1.0 mg/kg, n=10; Group A) after a compression injury. A group of methylprednisolone (MP)-treated (30 mg/kg, n=10; Group B) and non-treated animals (n=9; Group C) were included for comparison. The functional motor outcome such as inclined plane (IP), toe spreading reflex (TSR), and modified Tarlov scale (TS) were measured in each animal at regular time points up to 8 weeks post-treatment. Histologically the injury site was scored in four groups and immunohistochemically Wallerian Degeneration (WD), astrocytosis and expression of beta-amyloid protein was identified. RESULTS: In examining the IP data, no significant difference was recognized between the group means (P-value>0.5). For the TSR, there were no differences in the group responses. For the TS, the differences were not statistically significant. Only group B showed significance in cavitation scores compared to group A (P>0.0094), WD was significantly different than group C (P>0.03), astrocytosis was significantly higher than group A (P>0.001) and modest presence of beta-amyloid protein. CONCLUSION: Our data indicate that one time bolus administration of MK-801 lacks any significant effect on axonal function in chronically injured rats. Daily bolus administration of MP at 30 mg/kg also did not ensure a better functional outcome. Immunohistochemically we have been able to show significant differences in WD, astrocytosis and small insignificant changes in beta-amyloid protein.