Study On The Correlation Between Connexin43and Spinalcord Injury Of Rats

Objective To preliminarily explore the correlation between connexin43and spinal cord injury and provide laboratory basis for clinical spinal cord injury therapy through establishment of the rat model of spinal cord injury, behavior observation and determination of the expression changes ofGFAP, Cx43mRNA and protein.Methods36healthy adult SD rats were selected and randomly divided into two groups, the sham operation group (n=6) and the model group of spinal cord injury (n=30，according to different time points were randomly divided into five groups.)， For rats in the sham operation group, vertebral plate was opened and spinal cord was exposed, but no spinal cord injury was made. For the model group of spinal cord injury, optimized Allen method was adopted to establish T10spinal cord injury model of rat. BBB scale was used to evaluate the grade of spinal cord function of rats in each group after operation, at time points of6h,12h,1d,3d and5d respectively. Spinal cord tissue from the injured area was taken to determine the expression changes of connexin43(Connexin43, Cx43) and glial fibrillary acidic protein (GFAP) by reverse transcription polymerase chain reaction (RT-PCR) and western-blot, and one-factor variance analysis was also performed.Result (1) Result of BBB scale: BBB scale showed that the function of spinal cord nerve was normal with BBB scale reaching20points in the sham operation group; BBB scale in the model group of spinal cord injury increased along with time increasing, and P＜0.01was noted when the time points of the spinal cord injury group were compared with those of the sham operation group.(2) Result of reverse transcriptase polymerase chain reaction (RT-PCR): CX-43mRNA level began to increase in the first day of spinal cord injury and reached the peak in the3rd day, then decreased gradually but still higher than normal level. GFAP level increased gradually along with the time points after spinal cord injury, and still gradually increased in the7th day after operation. The variance analysis of the time points between groups showed statistical significance (P＜0.05).（3）Result of western-blot: Connexin43level began to increase in the first day of spinal cord injury and reached the peak in the3rd day, then gradually decreased but still higher than the normal level. GFAP level increased gradually along with the time points after spinal cord injury, and the gradual increasing was still observed in the7th day after operation. Statistical significance was observed through the variance analysis of the time points between groups (P＜0.05).Conclusion Preliminary exploration demonstrated that connexin43may be involved in the pathological process of spinal cord injury through observation on the changes of connexin43and GFAP.