We examined whether morphine reduced the behavioral signs of neuropathic pain below level induced by T13 spinal hemisection in rats. In order to examine the effect of morphine on the mechanical allodynia, morphine alone, morphine with naloxone and saline were administered intraperitoneally and intrathecally and behavioral tests were conducted. In systemic injection, mechanical allodynia was reduced only when a higher concentration of morphine (5 mg/kg) was used. Intrathecally injected morphine (0.5, 1, 2, 5 μg) reduced mechanical allodynia dose-dependently. It is suggested that systemic morphine has limited effect on mechanical allodynia but direct spinal administration of morphine is more effective in controlling central pain following spinal cord injury.
|Number of pages||4|
|Publication status||Published - 2003 May|
- Neuropathic pain
- Spinal cord injury
ASJC Scopus subject areas