of early drug administration on experimental spinal cord injury

本研究旨在探讨甲基强的松龙(MP)对大鼠脊髓损伤后脊髓血流量(SCBF)的影响。20只Wistar大鼠于140g造成T7-8脊髓急性夹伤，持续3s。伤后30min静脉注射生理盐水30 mg/kg或60 mg/kg，伤后2小时用放射自显影技术测定损伤部位及邻近部位的SCBF。生理盐水组和MP 30 mg/kg组。并于伤后6h测量SCBF。5只大鼠作为正常对照组。为评估实验性脊髓损伤的严重程度，对4只大鼠造成夹伤，每周用斜面法进行运动功能检查，连续6周。伤后2小时，所有大鼠损伤部位及邻近区域灰质SCBF明显降低。损伤部位脑白质SCBF也明显降低。在吻部和尾部，MP 30 mg/kg和60 mg/kg组大鼠脑白质SCBF显著降低。生理盐水组吻侧白质SCBF未见下降，尾侧略有升高。伤后6h，生理盐水组和甲基强的松龙30 mg/kg组大鼠灰质和白质SCBF逐渐减少。6小时SCBF值两组间差异无统计学意义。因此，创伤后SCBF至少在伤后6小时内呈进行性下降。甲基强的松龙30 mg/kg或60 mg/kg治疗不能改善大鼠脊髓创伤后缺血。

This project was planned to investigate effects of methylprednisolone (MP) on spinal cord blood flow (SCBF) after spinal cord injury in the rat. Twenty Wistar rats received acute clip compression injury of the T7-8 spinal cord at 140g for 3 seconds. Thirty minutes after injury, the rats received intravenous injection of saline, 30mg/kg, or 60mg/kg MP.At 2 hours after injury, SCBF was measured with the autoradiographic technique at the injury site and the adjacent areas. In the saline and 30mg/kg MP groups. SCBF was also measured at 6 hours after injury. Five rats were used for normal controls. To estimate the severity of the experimental spina cord injury, 4 rats underwent the clip compression injury and the motor function was examined weekly with an inclined plane method for 6 weeks. At 2 hours after injury, SCBF of the gray matter was severely decreased at the injurysite and adjacent areas in all rats. The white matter SCBF was also markedly decreased at the injury site. At the rostral and caudal sites, SCBF of the white matter was significantly decreased in the 30mg/kg and 60 mg/kg MP groups. However, the white matter SCBF in the saline group was not decreased at the rostral sites, and was slightly increased at the caudal areas. At 6 hours after injury, SCBFs of the gray and white matter were progressively decreased in the saline and 30mg/kg MP groups. There was no significant difference of the SCBF values at 6 hours between the groups. Thus, posttraumatic SCBF was progressivaly decreased at least until 6 hours after injury. Treatment with 30mg/kg or 60mg/kg MP did not improve the posttraumatic ischemia in the rat spinal cord.