The effect of pentoxifylline on existing hypersensitivity in a rat model of neuropathy.

BACKGROUND Using a rat L5 spinal nerve transection model we previously showed that pentoxifylline prevents hyperalgesia through antiinflammation in the prefrontal brain. In this study, we examined efficacy when applied after injury. METHODS We examined the effect of pentoxifylline on existing mechanical allodynia, observing glial activation and proinflammatory cytokine expression in the lumbar spinal cord, when given 7 days after L5 spinal nerve transection. RESULTS There was no effect from pentoxifylline on existing hypersensitivity, glial activation, and cytokine expression when applied after L5 spinal nerve transection. CONCLUSION Pentoxifylline administered intraperitoneally on day 7 postsurgery failed to alleviate existing hypersensitivity, or reduce glial activation and cytokine expression.