Protective effects of hyperbaric oxygen on the expression of Fas/Fas1 and apoptosis of neurocytes following spinal cord injury in rats

Abstract

Objective To investigate effect of hyperbaric oxygen on the expression of Fas/Fas1 and apoptosis of neurocytes following spinal cord injury in rats and also to explore the treatment effect and mechanism of HBO on spinal cord injury. Methods The rat model of acute spinal cord injury was developed with Allen's weight dropping. Following spinal cord injury, 120 SD rats were randomly divided into 4 groups:the hyperbaric oxygen (HBO) group, the high pressure nitrogen with normal oxygen group, the normal oxygen group and the normal pressure air group. Segments of the injured spinal cord were collected for morphological studies at 1,2, 3, 7, 11 days following injury. Apeptosis cells were labeled with Tunel and the expression of caspase-3 and Fas/Fas1 was determined with immunohistochemistry. Results were observed under the optical microscope and analyzed with SPSS11.5 statistics software. Results The level of Tunel-positive cells increased at 1 d and peaked at 3 d following injury. The level of Fas/Fas1 elevated at 1 d and peaked at 2 d after trauma.Expression of caspase-3 was similar to that of Fas/Fas1. When compared with those of the other groups, Tunel-positive cells in the HBO group decreased with statistical significance at 3 d after injury (P < 0.01).Conclusions HBO could decrease the expression of caspase-3 and Fas/Fas1 and inhibit cell apoptosis in rats following spinal cord injury, which might play a certain role in the protection of neurons following secondary SCI. Key words: Spinal cord injury; Hyperbaric oxygen; Apoptosis; Caspase-3; Fas/Fas1