Evaluation of drug effects on spinal cord injury--an experimental study in monkeys

Contusion injury is produced experimentally in anaesthetised monkeys by weight drop method. A group of animals having laminectomy alone served as sham controls. Drugs were administered 30 min after injury initially. Naloxone and nifedipine were administered as single dose administration immediately after injury. Dipyridamole and DMSO were administered daily for a period of 1 week. Acetylcholinesterase (AchE) was estimated in 2 spinal tissue segments, S1-at the site of injury and S2-the segment above the site of injury, at the end of 1 week after sacrificing the animals. Contusion injury produced significant decrease in specific activity of AchE in the traumatised segment of the experimental animals. The non-traumatised adjacent segment did not show any significant change. Nifedipine, naloxone and DMSO produced a decrease in AchE activity in S1 and S2 segments. Monkeys developed paraplegia after contusion injury. A score 2+ was observed after 1 week as compared to the score of 4+ of sham controls. Single dose administration of naloxone seemed to reverse the motor deficit by getting a score of 3+; other drugs did not produce any beneficial effect on motor deficit.