title: Neurotoxicity of intrathecal injections of dexmedetomidine into the rat spinal dorsal horn.
abstract: To investigate the neurotoxicity of intrathecal injections of dexmedetomidine, Sprague-Dawley rats were intrathecally injected with dexmedetomidine at doses of 0.75, 1.50 and 3.00 μg/kg into the spinal dorsal horn. We found that c-Fos expression in the rat spinal dorsal horn peaked at 7 hours following the 3.00 μg/kg dexmedetomidine injection, while the levels of c-Fos expression following 0.75 and 1.50 μg/kg dexmedetomidine were similar to those in the spinal dorsal horn of normal rats. At 48 hours following administration, the level of c-Fos expression was similar to normal levels. In addition, the intrathecal injections of dexmedetomidine increased paw withdrawal mechanical thresholds and prolonged thermal tail flick latencies. These results indicate that dexmedetomidine has pronounced antinociceptive effects. However, dexmedetomidine appears to have neurotoxic effects in the spinal cord because it increased c-Fos expression in the spinal dorsal horn within 7 hours following administration.
authors.affiliation: Department of Anesthesiology, Renmin Hospital of Wuhan University, Wuhan 430060, Hubei Province, China.
authors.forename: Jiabao
authors.initials: J
authors.lastname: Hou
authors.affiliation: Department of Anesthesiology, Renmin Hospital of Wuhan University, Wuhan 430060, Hubei Province, China.
authors.forename: Zhongyuan
authors.initials: Z
authors.lastname: Xia
authors.affiliation: Department of Anesthesiology, Renmin Hospital of Wuhan University, Wuhan 430060, Hubei Province, China.
authors.forename: Xingpeng
authors.initials: X
authors.lastname: Xiao
authors.affiliation: Department of Anesthesiology, Renmin Hospital of Wuhan University, Wuhan 430060, Hubei Province, China.
authors.forename: Xing
authors.initials: X
authors.lastname: Wan
authors.affiliation: Department of Anesthesiology, Renmin Hospital of Wuhan University, Wuhan 430060, Hubei Province, China.
authors.forename: Bo
authors.initials: B
authors.lastname: Zhao
keywords: dexmedetomidine; drug toxicity; fos; paw withdrawal mechanical threshold; spinal cord; thermal tail flick latency