脊髓康对大鼠脊髓损伤后神经功能恢复及脑源性神经营养因子表达的影响

目的探讨脊髓康对脊髓损伤(SCI)后神经功能恢复以及脑源性神经营养因子(BDNF)蛋白和mRNA表达的影响。方法144 只雌性Sprague-Dawley 大鼠，体质量180~220 g，随机抽取24 只作为假手术组，仅咬除T9~T11段椎板、棘突。其余采用改良Allen 法成功建立SCI 动物模型后，随机分为5 组，即模型组、醋酸泼尼松组及脊髓康高、中、低剂量组，每组24 只。脊髓康高、中、低剂量组分别按生药剂量50 g/(kg &#8901; d)、25 g/(kg &#8901; d)、12.5 g/(kg &#8901; d)灌胃；醋酸泼尼松组以醋酸泼尼松0.06 g/(kg &#8901; d)灌胃；假手术组与模型组均以同体积生理盐水灌胃。分别于术后24 h、3 d、7 d、14 d，进行Basso-Beattie-Bresnahan(BBB)评分、斜板试验，干预后3 d、7 d、14 d 处死大鼠取脊髓样本，采用免疫组化、Western blotting、荧光定量PCR法检测脊髓损伤区BDNF蛋白和mRNA的表达情况。结果术后24 h 假手术组大鼠BBB评分、斜板试验角度明显高于其他各组(P<0.01)。术后3~14 d 脊髓康中剂量组和醋酸泼尼松组BBB评分均高于模型组(P<0.05)，且术后14 d 脊髓康中剂量组BBB评分明显高于其他各组(P<0.01)。免疫组化和Western blotting 显示，不同时间点醋酸泼尼松组和脊髓康中剂量组BDNF蛋白表达水平均明显高于模型组(P<0.01)，二者具有等效性(P>0.05)。荧光定量PCR显示，醋酸泼尼松、脊髓康可促进SCI后脊髓损伤区BDNF mRNA的表达，早期醋酸泼尼松效果较为明显，而干预后14 d 脊髓康中剂量效果明显优于醋酸泼尼松。结论脊髓康可促进大鼠SCI后神经功能的恢复，提升SCI后脊髓内BDNF蛋白及mRNA的表达水平。

Effect of Jisuikang on Neural Functional Recovery and Expression of Brain-derived Neurotrophic Factor after Spinal Cord Injury in Rats

Objective To explore the effect of Jisuikang on neural functional recovery, and expression of brain-derived neurotrophic factor (BDNF) protein and mRNA level after spinal cord injury (SCI). Methods 144 female Sprague-Dawley rats, weighted 180 to 220 g, were used for experiment. 24 rats were randomly extracted into sham group (Group A), which had their vertebral plates and spines bitten away only.The others were randomly divided into model group (Group B), prednison group (Group C), and high, middle and low doses of Jisuikang group (Groups D to F) after SCI, 24 rats in each group. Group C was given 0.06 g/(kg &#8901; d) prednison, and Groups D to F were given 50, 25 and 12.5 g/(kg &#8901;d) Jisuikang respectively, which were given 20 ml/(kg &#8901;d) volume by intragastric administration. Groups A and B were given the same volume of normal saline (NS). The Basso-Beattie-Bresnahan (BBB) scores and oblique board test were applied to test the postoperative results 24 hours, 3, 7 and 14 days after SCI. The rats were executed and the spinal cord tissues were extracted 3, 7 and 14 days after SCI. Immunohistochemistry, Western blotting and RQ-PCR were applied to test the expression of protein and mRNA of BDNF. Results BBB scores and angle of oblique board test were significantly lower in Groups B to F than in Group A 24 hours after SCI (P<0.01). BBB scores were higher in both Groups C and E than in Group B 3 to 14 days after SCI (P<0.05), and was significantly higher in Group E than in the other groups 14 days after SCI (P<0.01). The results of immunohistochemistry and Western blotting showed that the protein expression of BDNF were significantly higher in Groups C and E than in Group B at different time points in the injured area after SCI (P<0.01), while there was no significant difference between Groups C and E (P>0.05). The results of RQ-PCR showed that prednisone and Jisuikang promoted the expression of BDNF mRNA. Group C (prednisone) had a most obvious effect at the beginning while Group E was better than Group C 14 days after SCI. Conclusion Jisuikang can promote the neural functional recovery and the expression of BDNF on both protein and mRNA level in SCI rats.