| [Objective]: To observe the effects of high-dose methylprednisolone and rolipram on expression of NF and SYP in in juried spinal cord, and to study the possible therapy in spinal cord injury with the two drugs.[Materials and Methods]: 84 healthy adult srague-daweley rats (female),whose mean weight 220±20g, were divided into 14 groups at random: control group; spinal cord injury groups (1d group, 3d group , 7d group, 14d group, 21d group, 28d group); methylprednisolone groups (1d group, 3d group , 7d group, 14d group, 21d group, 28d group); rolipram group. The spinal cord injury at T12 segment of rats was made with modified Allen apparatus. BBB graded everyday before and after operation .After SCI, high-dose methylprednisolone (30mg/kg) was immediately injected into abdominal cavity. One hour later, the 23-hour dose was calculated by 5．4mg/kg. h, and divided into four times for intraperitoneal injection. The rats were killed in different days. The fixed spinal cord segments (the T12 spinal cord segments) were taken out from the rats. These tissues were made into frozen sections in 25μm thickness, taken one section every two. The immunohistochemical ABC method was applied to detect the distribution and expression of NF and SYP in spinal white and gray matter in different days after SCI. All datas were analyzed by one-way anova, SNK-q test and paired-t test.[Result] 1．The pathological observing: There were significantly haemorrhage, edema, degeneration, vacuole in SCI groups. But the pathological changes of spinal cord were significantly improved in MP and ROL groups. 2．The change of NF positive axons on amount: The number of NF positive axons came to decrease in 1d, 3d, 7d, and increase in14d, 21d,28d. The number of NF positive axons belowed 1d group in 28d group. The change of NF positive axons on amount The MP group was similar with SCI group on number of NF positive axons. The MP groups' number of NF positive axons was lower than the SCI groups' in 1d and they were similar in 3d. But it was significantly higher than the SCI groups' in 7,14, 21, 28d. In 28d the MP groups' number of NF positive axons was significantly higher than 1d groups' , still to remain lower than control group. The ROL groups' number of NF positive axons was significantly higher than the SCI groups' in 28d.3．The change of NF positive axons on gray scale: The gray scale of NF positive axons increased gradually in 1d, 3d, 7d, and decreased in 14d, 21d, 28d. The MP groups' gray scale of NF positive axons were higher than the SCI groups' in 1d and they were similar in 3d. But it was significantly lower than the SCI groups' in 7,14, 21, 28d. In 28d, The ROL groups' number of NF positive axons was significantly higher than the SCI groups' .4．The changes of SYP positive axons on gray scale: The gray scale of NF positive axons came to increase in 1d, 3d, and decrease in 7d, 14d,21d, 28d. The MP groups' gray scale of SYP positive axons were higher than the SCI group' s in 1d and they were similar in 3d. But its were significantly lower than the SCI groups' in 7,14, 21, 28d. In 28d, The ROL groups' number of SYP positive axons were significantly higher than the SCI groups' .5．The handlimb locomotor function had being steady in control group.All animals' BBB scores were zero in 1 and increased gradually after it. The BBB scores of MP groups were significantly higher than the SCI groups' , still to remain lower than control group.[Conclusion] 1．The improved spinal cord injury model was practical and reliable and was accorded with clinic.2．The NF and SYP can objectly reflect the state of SCI and nerve function change, and may be quantizative indexes of SC regeneration.3．The improved handlimb locomotor function was positively correlativewith NF and SYP' s expression in SCI area.4．After SCI ,MP can not change the decomposition and reparation process of SC axons, but improve the regeneration of SC in midanaphase.5．The effect of ROL was obvious and reliable on SCI . |
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