Effect Of Propofol On The Expression Of NMDA Receptor In Spinal Segments Of L_4-6 After Sciatic Nerve Injury In Mice

Objective To observe the effects of propofol on nerve repair,nerve electrophysiology and expression of NMDAR2B in L_4-6-6 spinal cord after sciatic nerve injury in mice.Methods 96 healthy clean level male BALB/c mice aged 8 weeks and weighing18²2 g were selected.Random number table method was divided into sham group?sham group?,model group?M group?,propofol group?P group?,a total of three groups?n=32?.The right sciatic nerve injury model was established in group M and group P,while the right sciatic nerve injury just exposed and did not damaged in group Sham.After the preparation of the model,propofol was intraperitoneally injected into group P at 50 mg·kg^-1·d^-11 for 7 consecutive days.Sham group and M group were intraperitoneally injected with saline of equal volume.The mice in each group were randomly divided into 1,2,4 and 8 weeks groups?n=8?after drugs treatment.The conduction velocity and amplitude of sciatic nerve were measured by electrophysiological method at these four time points.After nerve electrophysiological examination,mice were sacrificed by decapitation.The injured sciatic nerves in group M and group P were cut off respectively and H-E staining was performed on the nerves0.5⁰.7 cm above below the anastomotic site,including the anastomotic site.The same part of the sciatic nerves in Sham group were cut for H-E staining,and the regeneration morphology of nerve fibers and the number of nerve fibers were observed by microscopic section.The expression of NMDAR2B in L_4-6-6 spinal cord segment of mice was detected by Western-blot and the expression of NMDAR2B in L_4-6-6 spinal cord segment of mice was detected by Real-time PCR.Results Compared with group M and group P,the sciatic nerve in Sham group had orderly arranged sciatic nerve fibers,the number of nerve fibers was large,there was no dissolution phenomenon and the action potential conduction velocity and amplitude were higher than those in group M and group P?P<0.05?.Compared with group M,the sciatic nerve in group P had orderly arranged sciatic nerve fibers,the number of nerve fibers increased,the dissolution phenomenon was less,and the action potential conduction velocity was higher and wave amplitude increased?P<0.05?.The expression of NMDAR2B subunit and NMDAR2B subunit mRNA in Sham group maintained a relatively constant level.Compared with Sham group,the expression of NMDAR2B subunit and the expression of NMDAR2B subunit in L_4-6-6 spinal cord segment of P group and M group were increased?P<0.05?;compared with M group,the expression of NMDAR2B subunit and the expression of NMDAR2B subunit were significantly decreased in P group?P<0.05?.Conclusion1.Propofol can promote the nerve repair after sciatic nerve injury in mice.2.Propofol can inhibit the expression of NMDAR2B in L_4-6-6 spinal cord segments.