Abstract: Objective To investigate the effect of ultrashort wave therapy on edema and inflammatory reaction after spinal cord injury (SCI) in rats. Methods 56 Sprague-Dawley rats were divided into sham- operated group (n=8), model group (n=24) and ultrashort wave group (n=24). The model was established with Allen's method. The sham-operated group was exposed endorhachis without hit. The ultrashort wave group was exposed to ultrashort wave radiation 7 minutes, once a day, 24 hours after modeling until the animals were sacrificed. Locomotors functional recovery was assessed every week post operation period by BBB score. Immunohistochemical staining was performed to observe the expression of the aquaporin-4(AQP-4) and ED-1. Results The BBB scores increased in the model group and the ultrashort wave group after treatment, and was higher in the ultrashort wave group than in the model group from 1 week after treatment (t>3.368, P<0.01). The expressions of AQP-4 and ED-1 were higher in the model group and ultrashort wave group than in the sham-operated group, and decreased as time went on. They were lower in the ultrashort wave group than in the model group(t>3.156, t>4.466, P<0.05). Conclusion Ultrashort wave therapy can alleviate the edema after SCI, reduce the activation and infiltration of inflammatory cells, and promote the recovery of neurological function.

Key words: spinal cord injury, ultrashort wave, aquaporin-4, macrophage/microglias, rats