Protective effect of methylprednisolone combined with hyperbaric oxygen treatment on spinal cord injury in rats

Objective To study the effect of methylprednisolone combined with hyperbaric oxygen on spinal cord injury in rats and expression of Beclin-1and transforming growth factor(TGF)-βprotein.MethodsExperimental animals were randomly divided into four groups: sham operation group, model group,methylprednisolone group and methylprednisolone combined with hyperbaric oxygen group(combined treatment group).There were 15 rats in each group.Spinal cord injury was induced by Allen's method.Intraperitoneal injection of normal saline was given in the model group.Methylprednisolone(30 mg/kg)was intraperitoneally injected in the methylprednisolone group.Methylprednisolone(30mg/kg)and 0.2MPa hyperbaric oxygen were given in the combined treatment group.All the treatments continued for 7d.Then myeloid tissue was taken from the rats and pathological section was made.Serum interleukin(IL)-1and IL-6were detected.Beclin-1and TGF-βprotein levels were measured by Western blot.Results Pathological results showed that the structure of spinal cord was intact and nerve cells grew normally in the sham operation group;the boundaries between spinal cord gray matter and white matter were unclear,and neuronal apoptosis and necrosis appeared in the model group;the boundaries between spinal cord gray matter and white matter were clear and tissue structural integrity presented,but vacuolar degeneration was obvious in nerve cells in the combined treatment group;spinal cord injury in the methylprednisolone group was more severe than that in the combined treatment group.Compared with those in the sham operation group,serum IL-1and IL-6levels and protein expression of Beclin-1and TGF-βin the model group,methylprednisolone group and combined treatment group were significantly increased(all P0.05).The above four parameters in the methylprednisolone group and combined treatment group were significantly lower than those in the model group(all P0.05),and the parameters in the combination treatment group were also significantly lower than those in the methylprednisolone group(all P0.05).Conclusion Methylprednisolone combined with hyperbaric oxygen is an effective treatment to reduce spinal cord injury in rats,which may be related to the downregulation of Beclin-1and TGF-βprotein.