| Objective:To explore the effect of neurite outgrowth and function recovery with co-application of ROCKII and GSK-3βinhibitors after spinal cord injury in rats. Methods:(1) 175 adult female Sprague-Dawley (SD) rats were randomly allocated into 5 groups after subjected to weight-drop impact causing complete paraplegia at T10 level and cathetered into subarachhnoid space via L4 level in each rats.Group A was treated with TDZD-8, Group B with Y27632, Group C with co-application of TDZD-8 and Y27632, Group D with PBS and Group E was sham operation group.The other 10 normal rats in group F was normal control group.Agent was injected into subarachhnoid space after SCI within 1 hour respectively (TDZD-8 with lmg/kg.d for 3 weeks,Y27643 with 1600ug/d for 2 weeks, TDZD-8 with lmg/kg.d for 3 weeks plus Y27643 with 1600ug/d for 2 weeks and PBS with 30uml/d for 3 weeks). In each group:the apoptosis of injured spinal cord was measured by TUNEL assay at 8,24hours and 1 week respectively and the expression of GAP-43 around the injured spinal cord was measured at 24hours,lweek and 2 weeks respectively.The BBB scors for hind limb motor function was evaluated at 3,6 and 8 weeks respectively and The SEP was measured at 3 and 8 weeks respectively.The neurite outgrowth was evaluated by anterograde tracing at 8 weeks. Results:The average cell numbers of apoptosis at 8,24hours and 1week in group F was fewer compared with group A to group E and it in group A to group C was fewer than in group D and group E respectively,and group c was the fewest of the five groups.There were no statistical different between group A and group B,and also between group D and group E.(2)The average positive areas of gap-43 expression at 24h,lw and 2w after SCI of group F was fewer than other groups. And group A to group C were wider than group D and group E,and group C was the widest of the five groups. Between group A and B,group D and E there were no statistical different.(3)From the normal group(group F),filaceous fluorescence with orderly distribution could been seen.Filaceous fluorescence or punctiform fluorescence with unorderly distribution could been seen in other groups. The average fluorimetric area of group A to group C was wider than group D and group E,and group C was the widest of the five groups.Between group A and B,group D and E there were no statistical different.(4)The score of normal rats was 21.The BBB scores of group F was significantly higher than other five groups.And group A,group B,or group C were higher than group D or group E.There were no statistical different among the group A,group B and group C,and between group D or group E. It might be due to the continuing compression caused by implanting the catheter into subbarachhonoid via L4 level.(5)Form group A to group E,the latent period was longer than the normal group(group F),and the amplitude was lower.The difference among the five groups(group A to group E)was similar to the BBB scores. Conclusion: co-application of Y27632 and TDZD-8 can are more effective of inhibiting apoptosis,alleviate secondary spinal cord injury, enhancing the expression of gap-43,promoting neurite outgrowthand facilitating the function recovery after SCI compared with Y27632 and TDZD-8 solely does. |
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