Effects of hyperbaric oxygen on the expressions of inflammatory factors in case of acute spinal cord injury in rats

Objective To investigate the effects of early HBO therapy on the expressions of pro inflammatory cytokine mRNA including tumor necrosis factor-α (TNF-α ) and interleukin-10 (IL-10) following spinal cord injury (SCI) in rats. Methods Forty SD rats were randomly divided into 3 groups:the sham operation group (n=4) , the SCI group (n = 18) , and the hyperbaric oxygen group (n = 18). Spinal cord injury model was developed by using the modified Allen impact. Then, the SCI group and the HBO group received HBO therapy 2 hours after injury, once a day. And 3 rats were randomly selected at 6, 12, 24, 72, 120 and 168 h following injury to take samples of injured spinal cord tissue and measure dynamic changes in the expressions of TNF-α, IL-10 mRNA by semi-quantitative RT-PCR method. Results Faint expression of the cytokine mRNA could be noticed in the sham group. The expression of TNF-α mRNA in the injured spinal cord tissue in the SCI group elevated gradually, increased obviously at 12 h after injury and reached peak at 24 h, and its high expression maintained till 72 h after injury. The tendency in the expression of TNF-α mRNA in the HBO group was identical to that of the SCI group, however, the amplitude in the increase of TNF-α mRNA decreased (P＜0. 05). The expression of IL-10 mRNA in the SCI group began to increase at 12 h after injury and increased gradually over time and reached peak at 168 h. The expressions of both TNF-α and IL-10 mRNA were more consistent in the HBO group, with more obvious increase in the expressions of IL-10 mRNA. Conclusions HBO could reduce the release of pro-inflammatory cytokines and increase the expression of anti-inflammatory cytokines,resulting in reduction of secondary spinal cord injury,protection of the damaged nerve cells and promotion of recovery. Key words: Spinal cord injury:Inflammatory cytokines; Hyperbaic oxygen; Inflammation