Effects of beforehand serotonin depletion on experimental acute spinal cord injury

选用体重300g左右的雄性wistar大鼠。试验组动物每日腹腔注射5-羟色胺合成抑制剂d， 1， -甲基酯-盐酸-对氯苯丙氨酸（p-CPA） （400mg/kg），连续3 d。对照组动物仅接受载药治疗。在最后一次注射后的第二天，用Sugita动脉瘤夹在T7硬膜外压迫脊髓3秒。用大鼠后肢运动等级和大鼠能维持自身的平面倾斜度来评价大鼠的功能恢复情况。功能恢复：实验组和对照组大鼠损伤后即刻后肢完全瘫痪。过了一个星期，又有了一点动静。平面倾斜度由损伤前的90降至损伤后的50。损伤脊髓组织学：两组大鼠损伤部位的坏死性血瘤均局限于中央灰质。光镜下HE染色未见实验组与对照组脊髓病变大小差异。胶质原纤维酸蛋白（GFAP）免疫反应性星形胶质细胞：实验组损伤部位及其尾节段星形胶质细胞的GFAP免疫反应性明显高于对照组。这些结果可能提示脊髓血清素的预先消耗对脊髓损伤后的继发性损伤几乎没有影响，但有可能在神经修复过程中发挥有利作用。

Male wistar rats weighting arround 300g were used. Animals in the experimental group were treated with d, 1, -methyl-ester-hydrochloride-p-chlorophenylalanine(p-CPA), a 5-HT synthesis inhibitor drug(400mg/kg) intraperitoneally daily for 3 consecutive days. Animals in the control group were treated with only the vehicle. On the next day after the last injection the spinal cords were injured by extradural compression at T7 for 3 seconds with Sugita aneurysm clip. Functional recovery of the rats was evaluated using motor grades of the hindlimbs and inclination of the plane at which a rat could maintain itself.1. Functional recovery : All rats in the experimental and control groups were completely paralysed in the hindlimbs immediately after the injuly. In a week some flicker of movement returned. The inclination of the plane decreased from 90ﾟ before injury to 50ﾟ after injury.2. Histology of injured spinal cord : The necrotic hemotomas had been exclusively localized in the central gray matter at the injury site in the rats of the both groups. Light microscopic study with HE staining did not show any difference in the size of the cord lesion between the experimental and control group.3. Glial fibrillary acid protein (GFAP) immunoreactive astrocytes : The GFAP immunoreactivity of astrocytes in the injury site and also at the segments caudal to it was more remarked in the experimental group than in the control group. Those results might suggest that beforehand depletion of serotonin in the spinal cord has almost no effect on the secondary damage of the cord following injury but has the possibility of playing a favorable role in neural reparative process.