川芎嗪对癫痫大鼠大脑神经元内氏小体的影响

背景:川芎嗪能对抗中枢神经系统的损伤作用,内氏小体结构的变化可作为神经元受损的标志.目的:探讨川芎嗪对癫痫大鼠大脑皮质神经元内氏小体结构及数目的影响.设计:观察对比实验.单位:咸宁学院医学院生理学教研室.材料:实验于2004-09/2005-03在华中科技大学同济医学院解剖学教研室完成.选择正常健康SD大鼠40只,三四月龄,体质量(250±50)g,雌雄不拘.方法:大鼠麻醉后开颅,暴露大脑皮质记录区域,采用BL-410生物功能实验系统记录左右两侧脑电,应用青霉素诱发青霉素致痫组和川芎嗪10 mg/kg,20 mg/kg,40 mg/kg组大鼠大脑皮质癫痫样放电.手术对照组在麻醉开颅手术1 h后取大脑;青霉素致痫组在青霉素诱发癫痫1 h后取大脑;川芎嗪10 mg/kg,20 mg/kg,40 mg/kg组在青霉素诱发癫痫放电稳定后,再分别腹腔注射川芎嗪10 mg/kg,20 mg/kg,40mg/kg,待抑制作用最明显时取大脑.分别制备脑组织切片,显示大脑皮质神经元内氏小体应用Thionine硫堇染色法,光镜下观察内氏小体结构的变化.采用HPIAS-1000高清晰度彩色病理图文报告系统对内氏小体染色结果进行定量检测,以每组标本15个视野吸光度的平均值作为该组内氏小体染色平均吸光度的测量值.主要观察指标:各组大鼠大脑皮质神经元内内氏小体的结构及数目变化.结果:40只大鼠全部进入结果分析,无脱失.①各组大鼠大脑皮质外颗粒层和外锥体细胞层神经元内氏小体结构的比较:手术对照组可见许多层深蓝色染色的块状或颗粒状内氏小体.青霉素致痫组内氏小体全部溶解或消失.川芎嗪10 mg/kg组内氏小体部分或全部溶解或消失.川芎嗪20 mg/kg组内氏小体数目较青霉素致痫组及川芎嗪10 mg/kg组明显增多.川芎嗪40 mg/kg组可见染成深蓝色、分布均匀呈块状或颗粒状的内氏小体,与手术对照组比较,结构基本恢复正常.②各组大鼠大脑皮质外颗粒层和外锥体细胞层神经元胞质内内氏小体染色平均吸光度的比较:青霉素致痫组的平均吸光度显著低于手术对照组0.033±0.002,0.756±0.035(t=4.93,P＜0.01)].川芎嗪20,40 mg/kg组的平均吸光度显著高于青霉素致痫组0.435±0.011,0.658±0.029(t=2.98,5.32,P＜0.01)].川芎嗪40 mg/kg组与手术对照组的平均吸光度相近(t=1.75,P＞0.05).结论:川芎嗪能显著提高癫痫大鼠神经元小体的含量.癫痫的发病过程可能与大脑神经元内氏小体的结构和含量的变化有密切关系,而川芎嗪能使神经元内氏小体的结构和含量得以恢复,调节内氏小体的功能,从而抑制癫痫发作.

Effect of tetramethylpyrazine on Nissl bodies in cerebral neurons of rats with epilepsy

BACKGROUND: Tetramethylpyrazine has the protective effect against the central nervous system injury. The structural changes in Nissl bodies were regarded as a marker of neuron injury.OBJECTIVE: To investigate the effect of tetramethylpyrazine on the structure and the quantity of Nissl bodies of cerebral neurons in rat with epilepsy.DESIGN: A comparative study.SETTING: It was conducted at the Physiological Department of Medical School of Xianning College.MATERIALS: From September 2004 to March 2005, it was completed at the Anatomy Department of Tongji Medical College, Huazhong University of Science and Technology. Forty healthy SD rats aging 3-4 months, weighing (250±50) g and regardless of their gender, were selected.METHODS: Rats underwent anesthesia and craniotomy. Then their cerebral cortex were exposed for placing BL-410 Experimental System of Biological Function (TME, China) to record the bilateral EEG of the brain and the seizure in rats with penicillin-induced epilepsy group and the 10 mg/kg tetramethylpyrazine group, 20 mg/kg tetramethylpyrazine group and 40 mg/kg tetramethylpyrazine group. In control groups, the brains of rats were taken out at 1 hour after craniotomy. In penicillin-induced epilepsy group, their brains were taken out at 1 hour after penicillin-induced epilepsy. In 10 mg/kg tetramethylpyrazine group, 20 mg/kg tetramethylpyrazine group and 40 mg/kg tetramethylpyrazine group, after stable penicillin-induced epilepsy, tetramethylpyrazine was injected intraperitoneally at a dose of 10 mg/kg, 20 mg/kg and 40 mg/kg, respectively.When the greatest protective effect of tetramethylpyrazine appeared, the rats' brains were taken out. Brain sections were sliced. Nissl bodies were stained by thionine staining. Under light microscope, structures of Nissl bodies were observed and the images of Nissl bodies were quantitatively analyzed by HPIAS-1000 high acuity color pathologic diagram-writing analyzing system. In each group, the average absorbency of 15 fields was regarded as the average absorbency of Nissl bodies in that group.MAIN OUTCOME MEASURES: In all the groups, the structure and the quantity of Nissl bodies of cortical neurons in rats were studied.of the structure of Nissl bodies in external granular layer cells and external pyramidal layer cells. In control group, multi-layer blue-stained and clumplike or granule-like Nissl bodies could be observed. In penicillin-induced epilepsy group, Nissl bodies were completely resolved and disappeared. In 10 mg/kg tetramethylpyrazine group, Nissl bodies were partly or completely resolved. In 20 mg/kg tetramethylpyrazine group, the quantity of Nissl bodies was significantly increased as compared with those in penicillin-induced epilepsy group and the 10 mg/kg tetramethylpyrazine group. In 40 mg/kg tetramethylpyrazine group, the quantity and the structure of of the average absorbency of stained Nissl bodies in external granular layer cells and external pyramidal layer cells in rat cortex among all the groups.In penicillin-induced epilepsy group, the average absorbency were dramatically lower than that in control group (0.033±0.002, 0.756±0.035, t=4.93,P ＜ 0.01). In 20 mg/kg tetramethylpyrazine group and 40 mg/kg tetramethylpyrazine group, the average absorbency were significantly higher than that in penicillin-induced epilepsy group (0.435±0.011, 0.658±0.029, t=2.98,5.32, P ＜ 0.01). In 40 mg/kg tetramethylpyrazine group, the average absorbency were similar to that in control group (t=1.75, P ＞ 0.05).CONCLUSION: Tetramethylpyrazine can significantly elevated the concentration of Nissl bodies of neurons in rats with epilepsy. Changes in the structure and quantity of Nissl bodies of cerebral neurons may be closely associated with seizure, and tetramethylpyrazine can restore the structure and the quantity of Nissl bodies of neurons, regulate their functions and hereby, inhibit seizures.