Postinjury treatment with magnesium sulfate attenuates neuropathic pains following spinal cord injury in male rats

Abstract

Spinal cord injury (SCI) has a number of severe and disabling consequences including chronic pain. Approximately 40% of patients experience neuropathic pain, which appears to be persistent. Previous studies have demonstrated the neuroprotective effects of magnesium sulfate (MgSO₄). We aimed to investigate the effect of MgSO₄ on neuropathic pains following SCI in male rats. Thirty-two adult male rats (weight 300–350 g) were used. After laminectomy, a complete SCI was induced by compression of the spinal cord for 1 min with an aneurysm clip. A single dose of 300 or 600 mg/kg MgSO₄ was injected intraperitoneally. Tail-flick latency and acetone drop test scores were evaluated before surgery and once a week for 4 weeks after surgery. Rats in groups SCI+Mg300 and SCI+Mg600 showed significantly higher mean tail-flick latencies and lower mean scores in the acetone test compared with those in the SCI+veh group 4 weeks after surgery (P<0.05). These findings revealed that systemic single-dose administration of MgSO₄ can attenuate thermal hyperalgesia and cold allodynia induced by SCI in rats.