The effects of rolipram on neurofunction and the ultrastructure of the spinal cord after spinal cord contusion / 中华物理医学与康复杂志

ABSTRACT

Objective To investigate the effects of rolipram on neurofunction and the ultrastructure of the spinal cord in rats with spinal cord contusion.Methods Thirty adult,female Sprague-Dawley (SD) rats received spinal cord contusion at the T10 level.They were then randomited into an experimental group and a control group immediately after the operation.Rats in the experimental group received subcutaneous injections of 0.25mg/kg of rolipram twice daily for two weeks.Control rats received the same dosage of 0.9％ sodium chloride solution on the same schedule.The rats'functional recovery was evaluated using the open-field locomotion rating scale of Basso,Beattie and Bresnahan (BBB score),once a week within the 1st month after spinal cord injury (SCI),and once every two weeks subsequently.The morphology of the spinal cord tissue around the lesion site was observed under the light microscope with HE staining at the 8th week postoperation,and the ultrastructure of the spinal cord was observed under the transmission electron microscope at the 2nd,4th and 8th week postoperation.Results At the 2nd and 3rd week after SCI the experimental group exhibited significandy greater improvement in average BBB scores than the control group.However,the average BBB scores in the experimental and control groups were not significantly different at 8 weeks after SCI.Under the light microscope,cavities were observed in the posterior dorsal column near the SCI in both the experimental and control groups.However thick,condensed glial scars in the injured area were observed only in the control group.The density of glial cells decreased more in the experimental group than in the control group.Transmission electron microscopy revealed that,compared with the control group,inflammatory edema was attenuated and fewer axons were damaged at the 2nd week postoperation in the experimental group.That group also showed less axon degeneration as well as more angiogenesis at the 4th and 8th week.Conclusion Rolipram can reduce secondary neuron degeneration,inhibit gliosis and the formation of glial scars,and promote angiogenesis.