Effects of dexmedetomidine or methylprednisolone on inflammatory responses in spinal cord injury

Background: The aim of this study was to compare the anti-inflammatory response of methylprednisolone and the α2-agonist dexmedetomidine in spinal cord injury (SCI).
Methods: Twenty-four male adult Wistar albino rats, weight 200–250 g, were included in the study. The rats were divided into four groups as follows: the control group ( n : 6) received only laminectomy; the SCI group ( n : 6) with trauma alone; the SCI+methylprednisolone group ( n : 6) with trauma and 30 mg/kg methylprednisolone, followed by a maintenance dose of 5.4 mg/kg/h; and the SCI+dexmedetomidine group ( n : 6) with trauma and 10 μg/kg dexmedetomidine treatment intraperitoneally. Twenty-four hours after the trauma, spinal cord samples were taken for histopathological examination and serum samples were collected for interleukin-6 (IL-6) and tumor necrosis factor (TNF)-α measurement.
Results: TNF-α ( P =0.009) and IL-6 ( P =0.009) levels were significantly increased in the SCI group. TNF-α and IL-6 levels were significantly decreased with methylprednisolone ( P =0.002, 0.002) and dexmedetomidine ( P =0.002, 0.009) treatment, respectively. Methylprednisolone and dexmedetomidine treatment reduced neutrophils' infiltration in SCI.
Conclusions: The current study does not clarify the definitive mechanism by which dexmedetomidine decreases inflammatory cytokines but it is the first study to report the anti-inflammatory effect of dexmedetomidine in SCI. Further studies are required to elucidate the effects of dexmedetomidine on the inflammatory response.