RESUMO
BACKGROUND:Rat models of complete spinal cord transection are common models for neural tissue engineering. After transecting the spinal cord by the previous methods, gap length of broken end cannot keep relatively uniform, so we cannot objectively evaluate effects of various treatments or tissue engineering materials. OBJECTIVE:The spinal cord transection models were established by using double edged micro scissors, andthe feasibility of this new model was explored by comparing with the conventional method. METHODS: A total of 42 adult female Sprague-Dawley rats were divided randomly into group A (n=6), group B (n=18) and group C (n=18). Group A only received laminectomy. In the group B, the spinal cord was transected with a sharp-pointed knife. Knife point should touch anterior wal of spinal canal and sidewal bone surface. Complete spinal cord transection models were prepared by repeated cutting. In group C, complete spinal cord transection models were established by using self-made double edged micro scissors. RESULTS AND CONCLUSION: (1) At 1 week after model establishment, in the groups B and C, complete paralysis of the hind limbs was found, and BBB scores were similar. However, significant differences in the spacing of broken end were detected. (2) At 4 weeks after model establishment, hind limb functions could restore to different degrees in both groups, but no significant difference in BBB scores was found. (3) At 8 weeks after model establishment, significant differences in hindlimb motor function scores were detectable between both groups. Biotin glucosamine tracer display: In group B, a few labeled axon fibers were observed at the caudal side of the injured spinal cord. In group C, spinal cord was completely transected, and labeled axon fibers cannot be found at the caudal side. (4) Results suggested that the modeling method of self-made double edged micro scissors could effectively eliminate individual differences, contribute to quantitative analysis and comparative study of therapeutic effects.